Estimating Sums and Differences (Whole Numbers) Worksheets
How to Practice Estimating Sums and Differences  Adding to numbers or finding their differences is not that difficult of a job once you get a hold of it and get yourself in practice. But in every case, things get complicated as you increase the number of digits or try to add or subtract more than two numbers. Finding the sum or difference of more than two numbers, or numbers with multiple digits can be a bit tough at first. However, still, things can be made easier by practice because that is what math is all about, practicing more and more to make it easier. Adding or subtracting two numbers on paper gets the actual and precise answer of a sum but also takes time. How about getting an estimate of a sum by doing it in your mind that consumes lesser time? Well, this is how you can get an estimate of addition or subtraction. While adding, it is simple. You just have to break down the digits into their place values and add them up. The same goes for subtraction. For example, while adding 243 with 567, you can break 243 in 200, 40, and 3. Similarly, break 567 into 500, 60, and 7. This way, things will become a lot easier, and sums answers to these sums can be estimated in mind, that too in lesser time. The same technique goes with subtraction.

Basic Lesson
Demonstrates how to estimate sums through the use of round estimation. Also includes practice problems. Estimate: 110 + 92 1. 110 Rounded to nearest whole number is 110. 2. 92 Rounded to nearest whole number is 90. Therefore, sum of 110 + 92 is 110 + 90 = 200.
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Intermediate Lesson
Uses a larger more difficult numbers to round than the basic lesson.
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Independent Practice 1
20 problems ask you to estimate sums and differences. The answers can be found below.
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Independent Practice 2
20 practice problems that review estimating sums and differences. The answers can be found below.
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Homework Worksheet
12 problems to reinforce the lessons and practice pages. An example is provided.
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