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Estimate Sums

Answer Keys Here

Aligned To Common Core Standard:

Grade 2 Base Ten - 2.NBT.B.7

How to Estimate Sums - Learning estimation of sums is essential when the students go in the phase to learn mental mathematics. Solving these operations mentally helps when you have to solve a bulk of calculations when adding simple numbers is the least of your worries. The best way to find this value is to round off to the nearest tens which makes it easier to solve. For instance, if you have two numbers, 16 and 11, to add. You can make 16 into 20 and 11 into 10. Add both 20 and 10 or a result 30, and then you can subtract the 4 which you added from 16 and add 1 which you subtracted from 11. The resultant answer is 27. The above mentioned method comes in handy when you are performing a bulk of calculations so that you don't have to write it. Rounding is a directly related skill to doing this properly and solving them with relative ease. This series of lessons and worksheets help students learn how to quickly get an idea of the final value of addition problems.

Printable Worksheets And Lessons

Homework Sheets

Matching is always fun for students and teachers alike.

  • Homework 1 - Write the letter of the estimated sum.
  • Homework 2 - If the digit that becomes zero is 0, 1, 2, 3, or 4, that digit becomes a zero and the digit to be rounded (the digit immediately to the left of it) remains the same.
  • Homework 3 - If the digit that becomes zero is 5, 6, 7, 8 or 9, that digit becomes a zero and the digit to be rounded is increased by one.

Practice Worksheets

We throw sums and differences in here to act as a quality practice experience.

  • Practice 1 - There are both addition and subtraction problems in here.
  • Practice 2 - Use the lines to your advantage.
  • Practice 3 - Lay some bricks of knowledge down here.

Math Skill Quizzes

Vertical practice with lines to help guide you along. Make sure not to lose site of the sums.

  • Quiz 1 - Estimate the sum of all problems.
  • Quiz 2 - Straight addition here.
  • Quiz 3 - A nice way to review this topic.