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Estimating Sums and Differences - Worksheet 8 - 3rd Grade

Hard

Practice estimating sums and differences using explicit place-value reasoning.

hard: Use another set to practice explaining and checking your answers.

23 problems · 10-15 minutes · Skills: estimation, rounding

About This Worksheet

This hard-level worksheet contains 23 problems designed for 3rd Grade students practicing estimating sums and differences. Hard worksheets feature challenging problems including multi-step questions, missing values, and real-world applications to push students further.

Recognize digits and read a place-value chart.

  • Practice estimating sums and differences using explicit place-value reasoning.
  • Check your result using the method in the example before moving to the next question.

How to Solve: Worked Example

Example Problem: Estimate 365 + 266 by first rounding each number to the nearest 10.
Solution Steps:
  1. 365 rounds to 370; 266 rounds to 270.
  2. Use the rounded values in the operation.
Answer: 640
Tip: Check your result using the method in the example before moving to the next question.
1
Estimate 967 + 367 by first rounding each number to the nearest 10.
2
Estimate 972 − 812 by first rounding each number to the nearest 10.
3
Estimate 483 + 294 by first rounding each number to the nearest 10.
4
Estimate 850 − 319 by first rounding each number to the nearest 10.
5
Estimate 795 + 765 by first rounding each number to the nearest 10.
6
Estimate 838 − 785 by first rounding each number to the nearest 10.
7
Estimate 800 + 773 by first rounding each number to the nearest 10.
8
Estimate 336 − 139 by first rounding each number to the nearest 10.
9
Estimate 253 + 106 by first rounding each number to the nearest 10.
10
Estimate 763 − 247 by first rounding each number to the nearest 10.
11
Estimate 341 + 164 by first rounding each number to the nearest 10.
12
Estimate 430 − 344 by first rounding each number to the nearest 10.
13
Estimate 709 + 134 by first rounding each number to the nearest 10.
14
Estimate 913 − 442 by first rounding each number to the nearest 10.
15
Estimate 682 + 535 by first rounding each number to the nearest 10.
16
Estimate 728 − 229 by first rounding each number to the nearest 10.
17
Estimate 672 + 188 by first rounding each number to the nearest 10.
18
Estimate 997 − 260 by first rounding each number to the nearest 10.
19
Estimate 630 + 505 by first rounding each number to the nearest 10.
20
Estimate 961 − 588 by first rounding each number to the nearest 10.
21
Estimate 509 + 477 by first rounding each number to the nearest 10.
22
Estimate 543 − 342 by first rounding each number to the nearest 10.
23
Estimate 933 + 324 by first rounding each number to the nearest 10.

Answer Key

1. 13402. 1603. 7704. 5305. 15706. 507. 15708. 2009. 36010. 51011. 50012. 9013. 84014. 47015. 122016. 50017. 86018. 74019. 114020. 37021. 99022. 20023. 1250

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Frequently Asked Questions

How do I download this estimating sums and differences - worksheet 8 worksheet?

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How do I find worksheets at different difficulty levels?

Each subtopic has 10 worksheets: Worksheets 1-3 are Easy, 4-7 are Medium, and 8-10 are Hard. Start with Easy worksheets to build confidence, then progress to harder ones.

What skills does this addition and subtraction worksheet cover?

This worksheet focuses on estimation, rounding. It is designed for 3rd Grade students and provides structured practice through varied problem types with a worked example to guide students before they begin.

Can I use this worksheet in my classroom?

Yes. All worksheets on K12Worksheets are free for classroom use. You can print copies for your entire class. With 10 worksheets per subtopic at three difficulty levels, you have plenty of options for differentiated instruction and individualized practice.

How many problems are on this worksheet?

This worksheet contains 23 problems. It typically takes 10-15 minutes to complete. An answer key with all solutions is included so parents and teachers can check work quickly.