3) Number: 640,700
the value of 4 in this number is 40,000
Number: 64,070
the value of 4 in this number is 4,000
So, times greater: 40,000 ÷ 4,000 = 10 times greater.
4)
The multiplication, 5 × 12 = 60. So, 5 × 120 = 600.
There is an extra zero at the very last of the result as '120' was multiplied with 5 instead of '12' which does not have zero at last which changes the result.
Similar cases with: 5 × 10 = 50. So, 5 × 100 = 500.