Question

A number is multiplied by 2. Then that product is multiplied by 5. Write to explain how you know what digit is in the ones place of the final product.

Answer 1

When you multiply a number by 5 and then by 2 it is the same as multiplying by 10. multiplying by 10 means you add a zero to the end of the number so the digit in the ones column will be always be zero