Summarize this article in one sentence.
Your child is probably already familiar with the concept of guessing. Explain that estimating is similar, but that the goal is to make educated guesses that are as accurate as possible. Learning how to estimate effectively will let you save time and energy in situations where an exact number is unnecessary. If you pay attention, you'll see examples of estimation frequently in your daily life. You might, for example, estimate how much your grocery bill will be, how long it will take you to drive somewhere, or how many cups of milk are left in the carton. Explain these examples to your child in a developmentally appropriate way. When you give these examples, it can help to explain why estimating, rather than calculating, is appropriate in the particular context. Tell your child, for example, that if you needed to know exactly what your grocery bill would be, you could add up all the prices and get a precise number, but, in this case, you're only trying to get an approximate number so that you don't spend too much. To reinforce the concept, show your child a flash card or picture with multiple objects on it: animals, toys, whatever your child likes. Show the card to your child, but not for long enough to count the objects, then ask your child to estimate the number. Give high scores to close estimates. Repeat the game until your child seems to understand the concept.

Summary:
Explain that estimation is like guesswork. Give examples. Use flash cards.