Question

Marta made a mistake while finding the product 84.15 × 10. She said that since she wanted to multiply 84.15 × 10 that she simply put a zero at the end to get her answer, 84.150. In your own words, explain Marta's misunderstanding. Please explain what she should do to get the correct answer and include the correct answer in your response.

Answer 1

When you multiply decimals by multiples of 10, you move the point to the right, as many times as the number of zeros.

For example:

$75.3456\times100$

100 has two zeros, therefore we move the point two places to the right:

$75.3456\times100=7534.56$

So, for the product:

$84.14\times10$

10 has one zero, therefore, we move the point one place to the right:

$84.14\times10=841.4$