Question

When is the estimation of products a useful tool?

Answer 1

The estimation of products is a useful tool when the numbers you have are either too big or too small and you need to make an equation easier to carry out.

Answer 2

One possible answer is:

When you are buying multiple items that have the same cost.

Explanation:

People often use estimation while shopping, to keep a sort of "running total" of their cost. If you are buying multiple items that have the same cost, estimating the total cost would help you keep track of your spending. To do this, we would estimate the product of the number of items and the cost per item.