Chapter 6
Mental Maths ( Page no. 84)
2. Fill in the blanks:
(a) 97 × 6000 = 97 × 6 × 1000
(b) 108 × 8000 = 108 × 8 × 1000
(c) 113 × 2000 = 113 × 2 × 1000
(d) 2516 × 9000 = 2516 × 9 × 1000
(e) 5000 × 398 = 398 × 5 × 1000
(f) 7000 × 784 = 7 × 784 × 1000
3. What will be the product if we multiply the double of 137 by the triple of 20?
Double of 137 = 2 × 137
= 274
Triple of 20 = 3 × 20
= 60
Product = 274 × 60
= 16,440
4. What will be the product if we multiply the triple of 235 by the double of 50?
Triple of 235 = 3 × 235
= 705
Double of 50 = 2 × 50
= 100
Product = 705 × 100
= 70,500
5. What will be the product if we multiply the difference between 49113 and 22568 by the double of 500?
Difference = 49113 – 22568
= 26,545
Double of 500 = 2 × 500
= 1000
Product = 26,545 × 1000
= 26,545,000
6. What will be the product if we multiply the sum of 35842 and 63808 by the triple of 300?
Sum = 35842 + 63808
= 99,650
Triple of 300 = 3 × 300
= 900
Product = 99650 × 900
= 89,685,000
