Why is it important to estimate?

Learning how to estimate is a valuable skill. Estimating helps you plan ahead and check your work to see if your answers make sense. As you saw in this video, Barkley was trying to estimate to see if he had enough pizza to feed his friends. He based his decision on prior knowledge or experience. He knew that he and Ted usually ate two slices of pizza. Barkley had six pizzas and was expecting to share them with two friends. Based upon Barkley's prior experiences with Ted, each friend could eat two full pizzas and Barkley would have lots of extra pizza.

The problem comes when we learn that Barkley's friends are "pizza loving gorillas." Barkley has no prior experience eating pizza with these friends. He can't estimate how much pizza is needed.

The ability to estimate also helps determine if answers to math problems are reasonable. Sometimes we round numbers to be able to add or subtract them more easily. When we do this, we can get a "rough idea" or an estimate of the correct answer.

Engineers and scientists (or anyone for that matter) can be caught in situations when they don't have a calculator available, but need to make decisions very quickly. They can use their ability to estimate to get a close answer so they can continue their work. Later, they can go back and check their estimate with a calculator.

The more practice or experience we have with numbers and amounts helps us estimate more accurately. This is a skill that we need to practice.