Question

The decimal 105.7 becomes 1,057 when multipled by 10. The same number becomes 10.57 when multipled by 0.10. Explain why.

Answer 1

Multiplication by 10 essentially moves the decimal point one position to the right which makes the number ten times larger because we are increasing the place value of each digit. This is the reason why 105.7
becomes 1057 when multiplied by 10
On the other hand, multiplication by 0.10 (which is same as dividing by 10 ) moves the decimal point one position to the left. This makes the number ten times smaller because we are decreasing the place value of each digit. This is why 105.7 becomes 10.57 when multiplied by 0.10.


Answer


The position of the decimal point in a number changes upon multiplication by 10 or 0.10 because the place value of each digit in the number changes.