Page 1 :
MATHEMATICS IN EVERYDAY LIFE–6, Chapter 6 : Decimals, , ANSWER KEYS, (iii) 347.39 = 3 × 100 + 4 × 10 + 7 × 1 + 3, , EXERCISE 6.1, 1., , 1, 1, (i) 5 × 10 + 0 × 1 + 1 ×, +2×, 10, 100, , = 50 + 0 +, , ×, , 3, 9, , 10 100, (iv) 3572.46 = 3 × 1000 + 5 × 100 + 7 × 10 + 2 × 1, , 1, 2, +, 10, 100, , = 300 + 40 + 7 +, , = 50.12, (ii) 9 × 1 + 6 ×, , 1, = 9.6, 10, , (iii) 4 × 10 + 8 × 1 + 2 ×, = 40 + 8 +, , 1, 1, +6×, 10, 100, 4, 6, , = 3000 + 500 + 70 + 2 +, 10 100, 5, 9, 6, (v) 0.596 =, , , 10 100 1000, 1, 1, 1, (vi) 49.831 = 4 × 10 + 9 × 1 + 8 ×, +3×, +, 100, 10, 1000, 8, 3, 1, , , = 40 + 9 +, 10 100 1000, 5, 3. (i) Sixteen and five hundredths = 16 +, 100, = 16.05, , +4×, , 1, 1, +7×, 10, 100, 2, 7, , 10 100, , = 48.27, (iv) 2 × 1000 + 5 × 100 + 4 × 10 + 6 × 1 + 8 ×, , 1, 10, 1, 100, , +2×, = 2000 + 500 + 40 + 6 +, , 8, 2, +, 10, 100, , (ii) Eight and six tenths = 8 , , = 2546.82, (v) 8 ×, , (iii) Five and sixty nine thousandths = 5 , , 8, 2, 3, , , 10 100 1000, = 0.823, , 1, 1, +4×, 10, 100, , +5×, , 1, 1000, , 3, 4, 5, , , = 10 + 6 +, 10 100 1000, 1, 1, 1, (ii) 7.003 = 7 × 1 + 0 ×, +0×, +3×, 10, 100, 1000, 1, 3, =7×1+3×, =7+, 1000, 1000, Mathematics In Everyday Life-6, , 3, = 0.003, 1000, (v) One hundred sixty two and six hundredths, 6, = 162 , = 162.06, 100, 3, 9, , 4. (i) 42 , = 42.39, 10 100, , (iv) Three thousandths =, , (i) 16.345, Expanded form :, 16.345 = 1 × 10 + 6 × 1 + 3 ×, , 6, = 8.6, 10, 69, 1000, = 5.069, , 1, 1, 1, +2×, ×3×, 10, 100, 1000, , =, 2., , 1, 1, +9×, 10, 100, , (ii) 72 , , 6, = 72.06, 100, , (iii) 285 , (iv) 7 , , 4, 3, , = 285.403, 10 1000, , 7, 6, 8, , , = 7.768, 10 100 1000, 1

Page 2 :
(vi) 0.91 or 0.899, Making like decimals, , EXERCISE 6.2, 1., , (i) 1.07 or 1.076, , 1. 0 7 0, , or, , 1. 0 7 6, , same, same, same, 0<6, , or, , 2., , (i), , (ii), , 12. 400, , (iii), , same, same, 3<4, , (iv), , Comparing the tenths digit, 3 < 4, Therefore, 12.356 < 12.400,  12.4 > 12.356, (iii) 0.56 or 0.76, 0. 5 6, , or, , 0. 7 6, , 1, 0.6, , 3., , 1, , 2, , (ii) 7.8 lies between 7 and 8. Then number 8 nearer, to 7.8 as shown on number line, , 7, , 8, , 3 8 . 98, , 7.8, (iii) 4.9 lies between 4 and 5. The number 5 nearer to, 4.9 as shown on number line., , Comparing tens place digit, 4 > 3,  46.13 > 38.98, (v) 1.006 or 1.6, Making like decimals., , 3, , 1. 6 0 0, , Comparing the tenths digit, 0 < 6, Therefore, 1.006 < 1.600,  1.6 > 1.006, , 4, , 5, 4.9, , (iv) 5.6 lies between 5 and 6. The number 6 nearer to, 5.6 as shown on number line, , same, 0<6, , 2, , 2.7, , 0.8, , 4>3, , 1. 0 0 6, , 3, , 1.8, , (i) 0.8 lies between 0 and 1. The number 1 is nearer, to 0.8 as shown on number line., , 6, , or, , 2, 1.3, , 0, , Comparing the tenths digit, 5 < 7, Therefore, 0.56 < 0.76,  0.76 > 0.56, (iv) 46.13 or 38.98, or, , Comparing the tenths digit, 9 > 8,  0.91 > 0.899, 0.6: 0.6 is greater than zero but less than 1., Starting from zero, the 6th part towards right, will represent 0.6 on number line., 1.3: 1.3 is greater than 1 but less than 2. Starting, from 1, the 3rd part towards right will represent, 1.3 on number line., 1.8: 1.8 is greater than 1 but less than 2. Starting, from 1, the 8th part towards right will represent, 1.8 on number line., 2.7: 2.7 is greater than 2 but less than 3. Starting, from 2, the 7th part towards right will represent, 2.7 on number line., , 0, , same, 5<7, , 4 6 . 13, , 0. 8 9 9, , same, 9>8, , Comparing the thousandths digit, 0 < 6, Therefore,, 1.07 < 1.076, or, 1.076 > 1.07, (ii) 12.356 or 12.4, Making like decimals., , 12. 356, , or, , 0. 9 1 0, , 4, , 5, , 6, 5.6, , 4., , (i) 2.1, 1.25, 1.284, 1.2, The number of decimal places in 2.1 = 1, The number of decimal places in 1.25 = 2, , Answer Keys

Page 3 :
The number of decimal places in 1.284 = 3, , Arranging in ascending order:, , The number of decimal places in 1.2 = 1, , 0.800, 1.080, 1.200, 1.208, Hence, 0.8, 1.08, 1.2, 1.208 are in ascending, order., (iv) 8.2, 8.02, 8.7, 8.17, 8.003, Converting into like decimals:, 8.200, 8.020, 8.700, 8.170, 8.003, Arranging in ascending order:, 8.003, 8.020, 8.170, 8.200, 8.700, Hence, 8.003, 8.02, 8.17, 8.2, 8.7 are in ascending, order., , We know that any number of extra zeros written, at the end of decimal number does not change, its value., For like decimals, four given decimal numbers, have same (three) number of decimal places., Thus, 2.100, 1.250, 1.284, 1.200 are like decimals,, (ii) 5.6, 5.06, 5.006, The number of decimal places in 5.6 = 1, The number of decimal places in 5.06 = 2, The number of decimal places in 5.006 = 3, For like decimals, three given decimal numbers, have same (three) number of decimal places., Thus, 5.600, 5.060, 5.006 are like decimals., , EXERCISE 6.3, 1., , (iii) 4.12, 4, 4.215, The number of decimal places in 4.12 = 2, The number of decimal places in 4 = 0, The number of decimal places in 4.215 = 3, For like decimals, three given decimal number, have same (three) number of decimal places., Thus, 4.120, 4.000, 4.125 are like decimals., (iv) 7.612, 7.21, 7.6, The number of decimal places in 7.612 = 3, The number of decimal places in 7.21 = 2, The number of decimal places in 7.6 = 1, For like decimals given decimal numbers have, same (three) number of decimal places., Thus, 7.612, 7.210, 7.600 are like decimals., 5., , (i) 18, 17.9, 18.02, 18.6, Converting into like decimals:, 18.00, 17.90, 18.02, 18.60, , Hence, 17.9, 18, 18.02, 18.6 are in ascending, order., (ii) 5.41, 5.01, 5.4, 5.14, Converting into like decimals:, 5.41, 5.01, 5.40, 5.14, Arranging in ascending order:, 5.01, 5.14, 5.40, 5.41, Hence, 5.01, 5.14, 5.4, 5.41 are in ascending, order., (iii) 1.2, 0.8, 1.08, 1.208, Converting into like decimals:, 1.200, 0.800, 1.080, 1.208, Mathematics In Everyday Life-6, , 26, 6, 6, 2, = 2, = 2 + 0.6 = 2.6, 10, 10, 10, , (ii), , 527, 7, 7, = 52  52 , = 52 + 0.7 = 52.7, 10, 10, 10, , (iii), , 29, = 0.0029, 10000, , (iv), , 7, = 0.07, 100, , (v), , 4537, 537, 537, 4, = 4, = 4 + 0.537 = 4.537, 1000, 1000, 1000, , (vi), , 329, 29, 29, 3, = 3, = 3 + 0.29 = 3.29, 100, 100, 100, , (vii), , 492, 92, 92, 4, = 4, = 4 + 0.92 = 4.92, 100, 100, 100, , (viii), , 2, = 0.002, 1000, , (ix), , 23, = 0.023, 1000, , 72, = 0.072, 1000, (i) 0.49, , (x), , Arranging in ascending order:, 17.90, 18.00, 18.20, 18.60, , (i), , 2., , Numerator of the fraction = 49, Denominator of the fraction = 100, (2 zeros are written after 1 as there are 2 decimal, places), Required fraction =, , 49, 100, , (ii) 0.093, Numerator of the fraction = 93, Denominator of the fraction = 1000, (3 zeros are written after 1 as there are 3 decimal, places), Required fraction =, , 93, 1000, 3

Page 4 :
(iii) 1.71, Numerator of the fraction = 171, Denominator of the fraction = 100, (2 zeros are written after 1 as there are 2 decimal, places), 171, Required fraction =, 100, (iv) 2.39, Numerator of the fraction = 239, Denominator of the fraction = 100, (2 zeros are written after 1 as there are 2 decimal, places), 239, Required fraction =, 100, (v) 0.021, Numerator of the fraction = 21, Denominator of the fraction = 1000, 21, Required fraction =, 1000, (vi) 0.103, Numerator of the fraction = 103, Denominator of the fraction = 1000, 103, Required fraction =, 1000, (vii) 0.0037, Numerator of the fraction = 37, Denominator of the fraction = 10000, Required fraction =, , 37, 10000, , 3., , (i) 0.6, Numerator of the fraction = 6, Denominator of the fraction = 10, (1 zero are written after 1 as there are 1 decimal, place), 3, 6, 3, Required fraction =, , 10 5 5, (ii) 7.5, Numerator of the fraction = 75, Denominator of the fraction = 10, (1 zero are written after 1 as there are 1 decimal, places), Required fraction =, , 4, , 21337, 100, , 75, , 15, , 10 2, , , , Required fraction =, , 15, 2, , 475, , 19, , 100 4, , , , 19, 4, , (iv) 5.25, Numerator of the fraction = 525, Denominator of the fraction = 100, Required fraction =, , 525, , 21, , 100 4, , , , 21, 4, , (v) 15.004, Numerator of the fraction = 15004, Denominator of the fraction = 1000, (3 zeros are written after 1 as there are 3 decimal, places), Required fraction =, , 15004, , 3751, , , , 1000 250, , 3751, 250, , (vi) 25.25, Numerator of the fraction = 2525, Denominator of the fraction = 100, (2 zeros are written after 1 as there are 2 decimal, places), Required fraction =, , (viii) 213.37, Numerator of the fraction = 21337, Denominator of the fraction = 100, Required fraction =, , (iii) 4.75, Numerator of the fraction = 475, Denominator of the fraction = 100, (2 zeros are written after 1 as there are 2 decimal, places), , 2525, , 101, , , , 100 4, , 101, 4, , (vii) 0.18, Numerator of the fraction = 18, Denominator of the fraction = 100, Required fraction =, , 18, , 9, , 100 50, , , , 9, 50, , (viii) 6.025, Numerator of the fraction = 6025, Denominator of the fraction = 1000, Required fraction =, , 6025, , 241, , 1000 40, , , , 241, 40, , (ix) 0.06, Numerator of the fraction = 6, Denominator of the fraction = 100, Required fraction =, , 6, , 3, , 100 50, , , , 3, 50, , Answer Keys

Page 5 :
(x) 0.125, Numerator of the fraction = 125, Denominator of the fraction = 1000, Required fraction =, , 125, , 5., , (ii) 126 , , 1, , , , 1000 8, , 1, 8, , (iii), , (xi) 0.05, Numerator of the fraction = 5, Denominator of the fraction = 100, Required fraction =, , 5, , 1, , 100 20, , 1, , 20, , (xii) 0.066, Numerator of the fraction = 66, Denominator of the fraction = 1000, Required fraction =, , 4., , (i), (ii), , 66, , 33, , 1000 500, , 33, , 500, , 14  2 28, 14, , =, = 2.8, 5  2 10, 5, , 32  2 64, 32, ,  6.4, =, 5, 5  2 10, , (v), , 2437  2 4874, 2437, ,  4.874, =, 500, 500  2 1000, , 201  125 25125, 201, ,  25.125, (vi), =, 8  125, 1000, 8, 315, 105 105  5 525, , , =, = 52.5, 6, 2, 25, 10, , (viii) 15, , 317 317  5 1585, 17, , ,  15.85, =, 20, 20  5, 100, 20, , (ix), , 74, 7, 28, ,  0.28, =, 25, 25  4 100, , (x), , 33, 11,  1.1, =, 30, 10, , (xi) 8, , 35 35  25 875, 3, , ,  8.75, =, 4, 4  25 100, 4, , (xii) 9, , 4, 49 49  2 98, , ,  9.8, =, 5, 5, 5  2 10, , Mathematics In Everyday Life-6, , 5, = 126.05, 100, , (iv) 600  10  5 , , 9, = 615.009, 1000, , 3, 6, = 27.036, , 100 1000, (i) 1 or 0.99, , (v) 20  7 , 6., , 1 . 00, , or, , 0 . 99, , 1>0, Comparing units place digit, 1 > 0,  1.00 > 0.99, hence, 1 > 0.99, (ii) 1.09 or 1.091, , 1. 0 9 0, , or, , 1. 0 9 1, , same, same, same, 0<1, , 49 49  125 6125, 1, , , =, = 6.125, 8, 8  125 1000, 8, , (iv), , 4, 1, ,  38.41, 10 100, , 7, 5, 4, , , = 0.754, 10 100 1000, , 3 3  25 75, , =, = 0.75, 4 4  25 100, , (iii) 6, , (vii), , (i) 30  8 , , Comparing hundredths place digit, 0 < 1,  1.09 < 1.091, hence, 1.091 > 1.09, (iii) 0.2 or 0.02, , 0. 2 0, , or, , 0. 0 2, , same, 2>0, Comparing tenths place digit, 2 > 0,  0.20 > 0.02, hence, 0.2 > 0.02, (iv) 5.2 or 5.02, , 5. 2 0, , or, , 5. 0 2, , same, 2>0, Comparing tenths place digit, 2 > 0,  5.20 > 5.02, hence, 5.2 > 5.02, , 5

Page 6 :
(v) 1.05 or 1.50, or, , 1. 0 5, , 1. 5 0, , 2., , same, 0<5, , Comparing the tenths place digit, 0 < 5,  1.05 < 1.50, hence, 1.50 > 1.05, (vi) 7.31 or 7.304, , or, , 7. 3 1 0, , 12, = `0.12, 100, , (ii) 75 paise = `, , 75, = `0.75, 100, , (iii) 20 paise = `, , 20, = `0.20, 100, , (iv) 2 paise = `, , (iii) 175 cm =, , 175, , 75 , m = 1 , m = 1.75 m, 100, , 100 , , 12, m = 0.12 m, 100, , (v) 760 cm =, , 760, , 60 , m = 7 , m = 7.60 m, 100, , 100 , , (vi) 685 cm =, , 685, , 85 , m = 6 , m = 6.85 m, 100, , 100 , , (vii) 5 cm =, , EXERCISE 6.4, (i) 12 paise = `, , 150, m = 1.50 m, 100, , 7. 3 0 4, , Comparing the hundredths place digit, 1 > 0,  7.310 > 7.304, hence, 7.31 > 7.304, , 5, m = 0.05 m, 100, , (viii) 3 m 25 cm = 3 m +, , (ix) 16 m 15 cm = 16 m +, , (x) 29 m 5 cm = 29 m +, , 5, m = (29 + 0.05) m, 100, , = 29.05 m, , = `35 + `0.60 = `35.60, , 3., , (i) 9 mm =, , 9, cm = 0.9 cm, 10, , (ii) 12 mm =, , (vi) 570 paise = `, , 570, , 70 , = ` 5 , = `5.70, 100, , 100 , , (iii) 176 mm =, , (vii) 245 paise = `, , 245, , 45 , = ` 2 , = `2.45, 100, , 100 , , (iv) 35 mm =, , 90, 100, = `50 + `0.90 = `50.90, , (viii) 50 rupees 90 paise = `50 + `, , 6, 100, , = `(1 + 0.06) = `1.06, 315, , 15 , = ` 3 , = ` 3.15, 100, , 100 , , ( 1 cm = 10 mm), , 12, cm = 1.2 cm, 10, 176, cm = 17.6 cm, 10, 35, cm = 3.5 cm, 10, 5, cm, 10, ( 1 cm = 10 mm), = 9 cm + 0.5 cm = 9.5 cm, , (v) 9 cm + 5 mm = 9 cm +, , (vi) 35 cm 8 mm = 35 cm +, , , 6 , = ` 1 , , 100 , , 6, , 15, m = (16 + 0.15) m, 100, , = 16.15 m, , 60, (v) 35 rupees 60 paise = `35 + `, 100, ( `1 = 100 paise), , (x) 315 paise = `, , 25, m = (3 + 0.25) m = 3.25 m, 100, , ( `1 = 100 paise), , 2, = `0.02, 100, , (ix) 1 rupee 6 paise = `1 + `, , ( 1 m = 100 cm), , (ii) 150 cm =, , (iv) 12 cm =, , same, same, 1>0, , 1., , 30, m = 0.3 m, 100, , (i) 30 cm =, , 8, cm, 10, , = 35 cm + 0.8 cm = 35.8 cm, (vii) 250 mm =, (viii) 21 mm =, , 250, cm = 25 cm, 10, 21, cm = 2.1 cm, 10, Answer Keys

Page 7 :
4., ,  1 km = 1000 m, ,  1m=, , (i) 19 m =, , 19, km = 0.019 km, 1000, , (ii) 28 m =, , 28, km = 0.028 km, 1000, , 1, km, 1000, , (iv) 75 km 6 m = 75 km +, , 6., , 6, km, 1000, , 8282, 282, km = 8, km, 1000, 1000, , 282, km, 1000, = 8 km + 0.282 km = 8.282 km, 7537, 537, km = 7, km, 1000, 1000, , 537, km, 1000, = 7 km + 0.537 km = 7.537 km, , = 7 km +, , (vii) 88 m =, , 88, km = 0.088 km, 1000, , (viii) 90 km 5 m = 90 km +, , 5, km, 1000, , = 90 km + 0.005 km = 90.005 km, 5., ,  1 kg = 1000 g  1 g =, , (i) 8 g =, , 1, kg, 1000, , 8, kg = 0.008 kg, 1000, , (ii) 125 g =, (iii) 3456 g =, , EXERCISE 6.5, , 125, kg = 0.125 kg, 1000, , 1., , 3456, kg = 3.456 kg, 1000, , (iv) 4 kg 800 g = 4 kg +, , 800, kg = 4 kg + 0.800 kg, 1000, , = 4.800 kg, (v) 46 kg 40 g = 46 kg +, , 40, g = 46 kg + 0.040 kg, 1000, , = 46.040 kg = 46.040 kg, Mathematics In Everyday Life-6, , 126, kg = 0.126 kg, 1000, (i) ` 9.25 = (9.25 × 100) paise ( `1 = 100 paise), , = 925 paise, (ii) 7.524 kg = (7.524 × 1000) g ( 1 kg = 1000 g), = 7524 g, (iii) 6.5 cm = (6.5 × 10) mm, ( 1 cm = 10 mm), = 65 mm, (iv) 8.5 km = (8.5 × 1000) m, ( 1 km = 1000 m), = 8500 m, (v) 16.007 kg = (16.007 × 1000) g, ( 1 kg = 1000 g), = 16007 g, (vi) 12.60 m = (12.60 × 100) cm ( 1 m = 100 cm), = 1260 cm, (vii) 25.25 m = (25.25 × 100) cm ( 1 m = 100 cm), = 2525 cm, (viii) 0.5 cm = (0.5 × 10) mm, ( 1 m = 10 mm), = 5 mm, (ix) ` 26.05 = (26.05 × 100) paise, ( `1 = 100 paise), = 2605 paise, (x) `125.50 = (125.50 × 100) paise, ( `1 = 100 paise), = 12550 paise, (xi) 2.13 km = (2.13 × 1000) m ( 1 km = 1000 m), = 2130 m, (xii) 0.008 kg = (0.008 × 1000) g ( 1 kg = 1000 g), =8g, , = 8 km +, , (vi) 7537 m =, , 8, kg = 4 kg + 0.008 kg, 1000, = 4.008 kg, , (viii) 126 g =, , = 75 km + 0.006 km, = 75.006 km, (v) 8282 m =, , 100, kg = 0.100 kg = 0.1 kg, 1000, , (vii) 4 kg 8 g = 4 kg +, , 686, km = 0.686 km, 1000, , (iii) 686 m =, , (vi) 100 g =, , (i) 0.002, 8.34, 25.08, Converting the given decimals into like decimals., We get, 0.002, 8.340, 25.080, Now, writing these decimals in columns and, adding,, 0.002, + 8.340, + 25.080, 33.422, Hence, the sum of given decimals is 33.422., 7

Page 8 :
(ii) 32, 0.542, 10.2, Converting the given decimals into like decimals., We get, 32.000, 0.542, 10.200, Now, writing these decimals in column and, adding., 32.000, + 0.542, + 10.200, 42.742, Hence, the sum of given decimals is 42.742., (iii) 25.032, 0.32, 0.008, Converting the given decimals into like decimals., We get, 25.032, 0.320, 0.008, Now, writing these decimals in columns and, adding., 25.032, + 0.320, + 0.008, 25.360, Hence, the sum of given decimals is 25.360., (iv) 23.89, 6.002, 2.6, Converting the given decimals into like decimals., We get, 23.890, 6.002, 2.600, 23.890, + 6.002, + 2.600, 32.492, Hence, the sum of given decimals is 32.492., (v) 0.82, 12.25, 3, Converting the given decimals into like decimals., We get, 0.82, 12.25, 3.00, 0.82, + 12.25, + 3.00, 16.07, Hence, the sum of given decimals is 16.07., (vi) 352.38, 26.2, 35, Converting the given decimals into like decimals., We get, 352.38, 26.20, 35.00, 352.38, + 26.20, + 35.00, 413.58, Hence, the sum of given decimals is 413.58., (vii) 0.35, 0.5, 3.8, 12.005, Converting the given decimals into like decimals., We get, 0.350, 0.500, 3.800, 12.005, 8, , 0.350, + 0.500, + 3.800, + 12.005, 16.655, Hence, the sum of given decimals is 16.655, (viii) 6.032, 8.45, 16.02, Converting the given decimals into like decimals., We get, 6.032, 8.450, 16.020, Now, writing these decimals in columns and, adding, 6.032, + 8.450, + 16.020, 30.502, Hence, the sum of given decimals is 30.502., (ix) 1, 0.5, 0.007, 2.5, Converting the given decimals into like decimals., We get, 1.000, 0.500, 0.007, 2.500, 1.000, + 0.500, + 0.007, + 2.500, 4.007, Hence, the sum of given decimals is 4.007, (x) 71.15, 1.306, 77.702, Converting the given decimals into like decimals., We get, 71.150, 1.306, 77.702, 71.150, + 1.306, + 77.702, 150.158, Hence, the sum of given decimals is 150.158, (xi) 281.234, 120.168, 35.1, Converting the given decimals into like decimals., We get, 281.234, 120.168, 35.100, 281.234, + 120.168, + 35.100, 436.502, Hence, the sum of given decimals is 436.502., (xii) 605.8, 105.76, 23.405, Converting the given decimals into like decimals., We get, 605.800, 105.760, 23.405, , Answer Keys

Page 9 :
2., , 605.800, + 105.760, + 23.405, , (ii) `52.75 + `32.25, `52.75, + `32.25, , 734.965, , `85.00, , Hence, the sum of given decimals is 734.965., (i) 16.1 + 1.161 + 116.00, Converting the given decimals into like, decimals, we get, 16.100 + 1.161 + 116.00, Writing these decimals in columns and adding., 16.100, + 1.161, + 116.000, , Hence, `52.75 + `32.25 = `85.00, (iii) 0.82 m + 13.45 m, 0.82 m, + 13.45 m, 14.27 m, Hence, 0.82 m + 13.45 m = 14.27 m, (iv) 36.34 m + 16 m, 36.34 m, + 16.00 m, , 133.261, , 52.34 m, , Hence, 16.1 + 1.161 + 116 = 133.261, (ii) 6.6 + 6.66 + 66.666, Converting the given decimals into like, decimals, we get, 6.600 + 6.660 + 66.666, Writing these decimals in columns and adding., 6.600, + 6.660, + 66.666, 79.926, Hence, 6.6 + 6.66 + 66.666 = 79.926, (iii) 0.02 + 2.02 + 2.002 + 2.0, Converting the given decimals into like, decimals, we get, 0.020 + 2.020 + 2.002 + 2.000, 0.020, + 2.020, + 2.002, + 2.000, 6.042, 3., , Hence, 0.02 + 2.02 + 2.002 + 2.0 = 6.042., Cost of exercise books, = ` 56.75, Cost of pencils, = + ` 26.30, Cost of geometry box = + ` 42.25, Total, , 4., , =, , `125.30, , Hence, for these purchasing he will spend, `125.30, (i) `32.40 + `16.75, `32.40, + `16.75, , Hence, 36.34 m + 16 m = 52.34 m, (v) 0.054 l + 26 l, 0.054 l, + 26.000 l, 26.054 l, Hence, 0.054 l + 26 l = 26.054 l, (vi) 23.009 kg + 0.006 kg + 2.4 kg, 23.009 kg, + 0.006 kg, 2.400 kg, 25.415 kg, Hence,, 5. Weight, Weight, Weight, , 23.009 kg + 0.006 kg + 2.4 kg = 25.415 kg, of I rice bag, = 82.000 kg, of II rice bag, = + 46.520 kg, of III rice bag, = + 32.050 kg, , Total weight, , = 160.570 kg, , Hence, total weight of rice in the bags = 160.570 kg, 6. First day earning, = ` 845.65, Second day earning, = + ` 485.36, Third day earning, = + ` 682.46, Fourth day earning, = + ` 389.80, Total earning, , =, , `2403.27, , Hence, total earning of four days = `2403.27, 7. Length of cloth for shirt, = 2.65 m, Length of cloth for trouser = + 2.35 m, Total length of cloth, , =, , 5.00 m, , Hence, Rohan purchased 5 m of cloths., , `49.15, Hence, `32.40 + `16.75 = `49.15, Mathematics In Everyday Life-6, , 9

Page 10 :
8. Weight of empty gas cylinder = 19.085 kg, Weight of gas containing in it = + 13.250 kg, =, 9., , =, , Hence, total quantity of oil, 422.53 l., Cost of Maths book, Cost of Science book, Cost of English text book, ,  316.97 – 217.35 = 99.62, (v) 0.512 from 4.2, 4.200, – 0.512, , 422.53 l, , 3.688,  4.2 – 0.512 = 3.688, (vi) 5.55 from 9.99, 9.99, – 5.55, , = ` 87.75, = ` 74.65, = + ` 38.46, =, , ` 200.86, , 4.44, , Hence, Sonu spends ` 200.86., Walking distance in the morning = 1.040 m, Walking distance in the evening = + 2.007 m, Total distance, , 12., , 99.62, , in these containers is, , Total cost, 11., , 32.335 kg, , Hence, total weight of filled cylinder is 32.335 kg., Capacity of first container, = 153.75 l, Capacity of second container = + 142.36 l, Capacity of third container = + 126.42 l, Total quantity, , 10., , (iv) 217.35 from 316.97, 316.97, – 217.35, , =, ,  9.99 – 5.55 = 4.44, (vii) 38.674 from 49.543, 49.543, – 38.674, , 3.047 m, , Hence, Rahul walk total 3.047 m in all., Distance covered by bus, = 10.352 km, Distance covered by rickshaw = + 2.006 km, Distance covered by foot, = + 0.200 km, Total distance, , 10.869,  49.543 – 38.674 = 10.869, (viii) 92.08 from 100, 100.00, – 92.08, , = 12.558 km, , Hence, the distance between the school and, residence is 12.558 km., , 7.92,  100 – 92.08 = 7.92, (ix) 359.84 from 700, 700.00, – 359.84, , EXERCISE 6.6, 1., , (i) 58.63 from 92.46, 92.46, – 58.63, , 340.16, , 33.83,  92.46 – 58.63 = 33.83, (ii) 36.785 from 38.02, , 2., , 38.020, – 36.785, , 3.711, , 1.235,  38.02 – 36.785 = 1.235, (iii) 86.786 from 88.82, 88.820, – 86.786, 2.034,  88.82 – 86.786 = 2.034, , 10, ,  700 – 359.84 = 340.16, The difference, 6 – 2.289 will gives us to the, required number to be added, 6.000, – 2.289, , 3., , Hence, 3.711 should be added., Difference of 5.24 and 2.163, = 5.24 – 2.163, = 3.077, 5.240, – 2.163, 3.077, , Answer Keys

Page 11 :
Now, the difference, 8 – 3.077 will gives us the, required number to be added., 8.000, – 3.077, 4.923, , 4., , Hence, 4.923 should be added., Difference of 623.42 and 565.604 = 623.420 – 565.604, = 57.816, 623.420, – 565.604, 57.816, Sum of 623.42 and 565.604 = 623.420 + 565.604, = 1189.024, 623.420, + 565.604, 1189.024, Now,, 1189.024, –57.816, 1131.208, , Hence, the difference of given decimals is 1131.208, less than their sum., 5. (i) 0.5 – 0.35, 0.50, – 0.35, 0.15, Thus, 0.5 – 0.35 = 0.15, (ii) 0.62 – 0.49, 0.62, – 0.49, 0.13, Thus, 0.62 – 0.49 = 0.13, (iii) 3.16 – 2.67, 3.16, – 2.67, 0.49, Thus, 3.16 – 2.67 = 0.49, 6. (i) ` 60 – ` 14.75, ` 60.00, – ` 14.75, ` 45.25, Thus, ` 60 – ` 14.75 = ` 45.25, , Mathematics In Everyday Life-6, , (ii) 0.36 m – 0.19 m, 0.36 m, – 0.19 m, 0.17 m, Thus, 0.36 m – 0.19 m = 0.17 m, (iii) `19 – `4.72, `19.00, – `04.72, `14.28, Thus, `19 – `4.72 = `14.28, (iv) 38.954 kg – 9.808 kg, 38.954 kg, – 9.808 kg, 29.146 kg, Thus, 38.954 kg – 9.808 kg = 29.146 kg, 7. Height of Akshat = 1.26 m, Height of Aakash = 1.3 m, Difference in height of both of them, = 1.3 m – 1.26 m = 0.04 m = 4 cm, 1.30 m, – 1.26 m, 0.04 m, Hence, Aakash is taller than Akshat by 4 cm., 8. Total length of two pieces of ribbon = 9 m + 3.35 m, = 12.35 m, 9.00 m, + 3.35 m, 12.35 m, Length of the remaining part of ribbon, = 17 m – 12.35 m, = 4.65 m, 17.00 m, – 12.35 m, 4.65 m, Hence, the length of remaining part is 4.65 m., 9. (i) 47.50 – 22.36 + 54.5, or 47.50 – 22.36 + 54.50 = 25. 14 + 54.50, = 79.64, Hence, 47.50 – 22.36 + 54.5 = 79.64, (ii) 568.75 + 309 – 249.50 – 12.56, or 568.75 + 309.00 – 249.50 – 12.56, = 877.75 – 249.50 – 12.56, = 628.25 – 12.56 = 615.69, Hence, 568.75 + 309 – 249.50 – 12.56 = 615.69, 11

Page 12 :
(iii) 56.4 – 8.333 – 9.707, = 56.400 – 8.333 – 9.707, = 48.067 – 9.707, = 38.360, Hence, 56.4 – 8.333 – 9.707 = 38.360, (iv) 112.60 – 26.48 – 0.78 + 12.047, = 112.600 – 26.480 – 0.780 + 12.047, = 86.120 – 0.780 + 12.047, = 97.387, Hence, 112.6 – 26.48 – 0.78 + 12.047, = 97.387, 10. Quantity of fruits purchased = 6.025 kg, Quantity of vegetables purchased = 4.325 kg, Total weight = 10.350 kg,  The bag contents weighs 12 kg, So, weight of empty bag = 12.000 kg – 10.350 kg, 12.000 kg, – 10.350 kg, 1.650 kg, Hence, the weight of empty bag is 1.650 kg, 11. The required number, will be the difference of 79.86, and 37.062., 79.860, –37.062, 42.798, 12., , Hence, 42.798 should be decrease., The required number will be difference of 60 and, 33.852., 60.000, – 33.852, , MULTIPLE CHOICE QUESTIONS, 1., , Hence, option (c) is correct., 2. 5 m 5 cm = 5 m +, , Total cost = `85.31, Amount paid = `100, Balance amount = `100 – `85.31, = `(100 – 85.31), = `14.69, Hence, the shopkeeper returns `14.69., 14. Total length of cloth, = 16.09 m, Length of piece of cloth = 7.50 m, Left of length of cloth, = 16.09 m – 7.50 m, = 8.59 m, Hence, 8.59 m length of cloth were left., 12, , 5, m = 5 m + 0.005 m, 100, , = 5.05 m, Hence, option (b) is correct., 3. Option (a) is correct., 1,  10 times = 1, 10, 4. 2.1, 2.01, 2.101, 2.11, Converting into like decimals, we get, , 2.100, 2.010, 2.101, 2.110, 2.11 > 2.101 > 2.100 > 2.010, Thus, 2.11 is the greatest, Hence, option (a) is correct., 5., , 8, , 4, 3, , = 8 + 0.04 + 0.003 = 8.043, 100 1000, , Hence, option (c) is correct., 6. 0.7 + 7.7 + 0.007 + 0.07, Converting into like decimals, we get, 0.700 + 7.700 + 0.007 + 0.070, 0.700, + 7.700, + 0.007, + 0.070, 8.477, Thus, 0.7 + 7.7 + 0.007 + 0.07 = 8.477, Hence, option (b) is correct., , 26.148, Hence, 26.148 should be increased., 13. Cost of exercise books = `71.56, Cost of cardsheet = `13.75, , 42, = 0.042, 100, , 7. 1 m =, , 1, km = 0.001 km, 1000, , Hence, option (d) is correct., 8. Eight hundred thirty six and seven hundredths, = 836 , , 7, = 836.07, 100, , Hence, option (a) is correct., 9., , 74, 7, 28, , =, = 0.28, 25  4 100, 25, , Hence, option (b) is correct., 10. The place value of 7 in 0.02784, 7, = 7 thousandths, 1000, Hence, option (c) is correct., , =, , Answer Keys

Page 13 :
11. 7.3 – 2.8 = 4.5, Hence, option (b) is correct., 12. The value of, , 4. ` 246.70 = 246 rupees and 70 paise, 5. 9 paise = ` 0.09, 6. 72 mm = 0.000072 km, , 61, = 0.0061, 10000, ,  72 mm =, , Hence, option (c) is correct., 13., , 14., , 9, 9, = 9, = 9.009, 1000, 1000, , =, , 72, 1, , m, 10 100, , Hence, option (b) is correct., , =, , 72, 1, 1, , , km, 10 100 1000, , =, , 72, km = 0.000072 km, 1000000, , 9, , 3, , 29 29  125 3625, 5, , , =, = 3.625, 8, 8  125 1000, 8, , 1, 1, 1, cm; 1 cm =, m, 1m =, km), 100, 100, 1000, 7. 2.13 kg = 2130 g,  2.13 kg = (2.13 × 1000)g = 2130 g, 8. 0.987 should be added to 2.013 to get 3., , Hence, option (c) is correct., 15., , 72, cm, 10, , 6, , ( 1 m =, , 7, 8, , = 6.078, 100 100, , Hence, option (a) is correct., 16. 0.64 – 0.064, 0.640, – 0.064, , , , 0.987, , 0.576, , 9. 1 + 0.06 = 1.06, 10. 2.4 + 5 – 6.1 = 1.3, , Thus, 0.64 – 0.064 = 0.576, Hence, option (a) is correct., 17. 3 kg 5 g = 3 kg +, , 5, kg, 1000, , REVIEW EXERCISE, , ( 1 kg = 100 g), , = 3 kg + 0.005 kg, = 3.005 kg, Hence, option (c) is correct., 18. 3.4, 3.04, 4.33, 4.03, 4.033, Converting into like decimals., 3.400, 3.040, 4.330, 4.030, 4.033, 4.330 > 4.033 > 4.030 > 3.400 > 3.040, Thus, 4.33 is the greatest., Hence, option (b) is correct., 19. The difference, 1 – 0.576 will gives us the required, number to be added., 1.000, – 0.576, 0.424, , 1., , 1, 1, 1, +8×, +3×, 10, 100, 1000, 8, 3, , =6+, 100 1000, = 6 + 0.08 + 0.003, , 2, 8, , = 0.02 + 0.008, 100 1000, 2. 0.8: 0.8 is greater than zero but less than 1. Starting, from zero the 8th part towards right will represent, 0.8 on the number line., 1.7: 1.7 is greater than 1 but less than 2. Starting from, the 7th part towards right will represent 1.7 on, number line., , (iii) 0.028 =, , 0, , Mathematics In Everyday Life-6, , 1, 0.8, , 3., , MENTAL MATHS CORNER, , 1, 2, 3, , , 10 100 1000, = 10 + 2 + 0.1 + 0.02 + 0.003, , (i) 12.123 = 10 + 2 × 1 +, , (ii) 6.083 = 6 + 0 ×, , Hence, option (c) is correct., 20. The decimal equivalent to 30.1 is 30.40., Hence, option (b) is correct., , 1. 0.1 + 11.20 = 11.30, 2. 11.37 – 0.9 = 10.47, 3. 4.17 + 1000 = 1004.17, , 3.000, – 2.013, , 2, 1.7, , 7, 3, , = 6.703, 10 1000, 7, 3, , (ii) 8 , = 8.073, 100 1000, 2, 3, 6, , , (iii) 20  9 , = 29.236, 10 100 1000, , (i) 6 , , 13

Page 14 :
4., , (i) 31.13, 3.113, 31.31, 31.313, 31, Converting into like decimals, we get, 31.130, 3.113, 31.310, 31.313, 31.000, 3.113 < 31.000 < 31.130 < 31.310 < 31.313,  3.113 < 31 < 31.13 < 31.31 < 31.313, Hence, 3.113, 31, 31.13, 31.31, 31.313 are in, ascending order., (ii) 24.60, 34.14, 13.06, 29.41, 13.06 < 24.62 < 29.41 < 34.14, Hence, 13.06, 24.62, 29.41, 34.14 are in ascending, order., 5. (i) 5.364, 5.634, 5.436, 5.453, 5.634 > 5.453 > 5.436 > 5.364, Hence, 5.634, 5.453, 5.436, 5.364 are in ascending, order., (ii) 1.627, 1.299, 1.217, 1.712, 1.712 > 1.627 > 1.299 > 1.217, Hence, 1.712, 1.627, 1.299, 1.217 are in descending, order., 6. (i) 4.125, The numerator the fraction = 4125, The denominator of the fraction = 1000, (3 zeros are written after 1 as there are 3 decimal, places), Required fraction =, , 4125, , 33, , Required fraction =, 7., , 1, , 5, , 1000, , 200, , , , 175, , 7, , 100 4, , , , 258.32, Hence, the sum of given decimals is 258.32., (iii) 1.5 and 0.005, 1.500, + 0.005, 1.505, Hence, the sum of given decimals is 1.505., (iv) 4.12, 1.3 and 7, Converting the given decimals into like, decimals, we get, 4.12, 1.30, 7.00, 4.12, + 1.30, + 7.00, , 7, 4, , Required fraction =, , 100, 14, , 117, 20, , , , (i) 4.21 and 1.06, , Thus, the sum of given decimals is 5.27., (ii) 4.2 and 254.12, Converting into like decimals, we get, 4.20, 254.12, Now, writing these decimals in columns and, adding, 4.20, + 254.12, , 1, 200, , 12.42, , (iv) 5.85, Numerator of the fraction = 585, Denominator of the fraction = 100, 585, , 4, 19, 19  2 38, =, =, = 3.8, , 5, 5, 5  2 10, , 5.27, , (iii) 1.75, Numerator of the fraction = 175, Denominator of the fraction = 100, (2 zeros are written after 1 as there are 2 decimal, places), Required fraction =, , 7, 7  125 875, , =, = 0.875, 8, 8  125 1000, , 4.21, + 1.06, , (ii) 0.005, Numerator of the fraction = 5, Denominator of the fraction = 1000, (3 zeros are written after 1 as there are 3 decimal, places), Required fraction =, , 3, = 0.003, 1000, 22 22  2 44, 2, , , (ii) 4 =, = 4.4, 5, 5  2 10, 5, , (iv) 3, 8., , 1525 61, , 100, 4, , (i), , (iii), , 33, 8, , , , 1000 8, , (v) 15.25, Numerator of the fraction = 1525, Denominator of the fraction = 100, , 117, 20, , 9., , Hence, the sum of given decimals is 12.42., (i) 6.45 – 0.645, 6.450, – 0.645, 5.805,  6.45 – 0.645 = 5.805, Answer Keys

Page 15 :
(ii) 7.234 – 6.467, 7.234, – 6.467, 0.767,  7.234 – 6.467 = 0.767, (iii) 3.3 – 0.333, 3.300, – 0.333, 2.967,  3.3 – 0.333 = 2.967, (iv) 65.2 – 42.71, 65.20, – 42.71, 22.49,  65.2 – 42.71 = 22.49, 10. Total quantity of milk = 12.12 l + 6.23 l = 18.35 l, 12.12 l, + 6.23 l, , 14. Cost of a pen, Cost of a pencil, , = `16.50, = + `2.25, , Total cost, = `18.75, Mohan paid to shopkeeper = `20, Balance amount = `20 – `18.75, = `1.25, Hence, the balance amount is `1.25., , HOTS QUESTIONS, 1. The tenths digit of required decimals = sum of 4, and 2 = 4 + 2 = 6, Hundredths digit = half of tenths digits =, , 6, =3, 2, , Thus, the required decimals = 0.63., 2. Last digit of required decimals = 3, Tenths digit = 0, Hundreths digit = 1, Thus, the required decimals = 0.013., 3. Three decimals between 5.85 and 5.86., 5.851, 5.852 and 5.853., , 18.35 l, Capacity of an empty can = 23 l, Therefore, 23 l – 18.35 l = 4.65 l of milk can be, proved., 11. The difference, 4.05 – 3.042 will give us the number, to be added., 4.050, – 3.042, 1.008, Hence, 1.008 should be added., 12. Sum at 13.96 and 18.02, 13.96, + 18.02, 31.98, The difference, 31.98 – 30 will gives the required, number., 31.98, – 30.00, 1.98, Hence, the required number is 1.98., 13. The difference, 900 – 628.488 will gives us the, required number, 900.000, – 628.488, , After putting the decimal point (.) between 6, and 8. We get, a number 6.8 which is greater, than 6 and smaller than 8., , VALUE BASED QUESTION, SUMMATIVE ASSESSMENT, Cost of a pencil box, Cost of a pen set, Cost of a paint box, , = ` 73.50, = + ` 68.75, = + `112.35, , Total amount, , =, , `254.60, , Amount paid to shopkeeper = `500, Balance amount, = `500 – `254.60, = `(500 – 254.60), = `245.40, (a) Yes, Rahul is correct in returning `100 back, to the shopkeeper., (b) Since, “Honesty is the best policy.” So, we, learn “Honesty” from this transaction., , 271.512, Hence, 271.512 is the required number., Mathematics In Everyday Life-6, , 15