3rd Grade Checking Reasonable Estimates Worksheet: Two-Step Problems

Sometimes a child in a story makes a guess, and the reader checks it. This 3rd grade checking reasonable estimates worksheet has two-step problems, labeled a and b. In a, Joice bakes 24 muffins, keeps 3 and shares the rest between 2 friends, and she guesses that each friend gets about 10. In b, Peter has 256 dimes, and his brother borrows half of them, and then Peter guesses that about 120 dimes are left. Your child solves each problem and then decides if the estimate is good. A girl walks on the right, while a boy stands next to a piggy bank. Page two explains both answers like a worked example.

Yes for a, no for b

In a, 24 − 3 = 21 muffins are shared. Rounded to the nearest ten, 21 is 20, and 20 ÷ 2 = 10, so the estimate is good. However, 21 muffins cannot be shared equally between 2 friends. So point out that one muffin is left over, or that each friend gets 10 and a half.

In b, half of 256 is 128, so 128 dimes are left, and rounded to the nearest ten, 128 gives 130. Since 130 is more than 120, the estimate is too low and the answer is no. Both answers in the key are right.

At the table: two steps, then a check

Ask your child to underline the two actions in each story, such as "kept 3" and "shared between 2". Then they write one calculation for each action, and after that, they round the result and compare it with the estimate. This order keeps the two steps apart, and the estimation comes last.

The key has slips to point out. Item a repeats words: "the estimate number of muffins of muffins". Item b says "really bigger", writes "peter" in lowercase and has stray commas. Also, "Joice" is an unusual spelling of Joyce, and a comma is missing after "Charles".

After the page: guess and check

Put 37 crayons in a box and say: "We give away 9 and split the rest between 2 friends. Is 15 each a good estimate?" Your child solves it, 37 − 9 = 28 and 28 ÷ 2 = 14, and then decides. Next, let your child invent a guess for you to check. Finally, compare both items with the answer key on page two.