Estimate, Then Solve
Round to the nearest hundred and estimate. Then solve in the grid. Is the answer close?
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This is sheet #73624601.
How to do it
- Round each number to the nearest hundred and estimate.
- Solve the problem in the grid.
- Check that the answer is close to the estimate.
Teaching tip
If the answer and the estimate are far apart, look for a mistake. This sheet is aligned with Common Core 3.NBT.A.2.
About this worksheet
Estimate each problem by rounding to the nearest hundred, then solve it exactly on graph paper.
What kids practice
Third graders add and subtract within 1,000, working toward doing it smoothly and accurately. They regroup in more than one column, like 476 + 358, and subtract from numbers with zeros, like 400 − 126. They also use mental strategies, estimate with rounding, and check subtraction with addition.
Watch for
- Forgetting to add the carried 1.
- Subtracting the smaller digit from the bigger one in each column, no matter which is on top.
- Regrouping across a zero but forgetting to change the zero to 9.
It's free to print, with Fewer, Standard or More on the page and an answer key. See the full three-digit addition and subtraction guide for 3rd grade.
More sheets in this set
- See it all
1. Adding and Subtracting Strategies ChartThree ways to add and subtract within 1,000, stacking with regrouping, counting up on a number line and breaking apart by place. 
2. Add with Regrouping TwiceThree-digit addition where both the ones and the tens carry, like 476 + 358.
3. Subtract with Regrouping TwiceThree-digit subtraction where both the ones and the tens need to regroup, like 523 − 268.
4. Subtract Across ZerosSubtracting from numbers with zeros, like 400 − 126 and 503 − 247.
5. Add or Subtract? (Mixed)Three-digit addition and subtraction mixed on one page.
7. Check with the OppositeSolve each problem, then check it with the opposite. Add to check subtraction and subtract to check addition.