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2.01 Estimation first

Lesson

Are you ready?

Do you remember how to round numbers?

The number $379$379 is plotted on the number line.

050100150200250300350400

  1.  

    Round $379$379 to the nearest $100$100 and plot it on the blank number line

    050100150200250300350400

Learn

Let's see how we can estimate the answer to a subtraction problem, and an addition problem.

Apply

We want to estimate the answer to $258-26$25826.

  1. Round each of the two numbers to the nearest $10$10:

      $258-26$25826
    is rounded to $\editable{}-\editable{}$ $=$=$\editable{}$
  2. Find the value of $258-26$25826.

Remember!

If we don't need an exact answer to a problem, we can use estimating to find out a close-enough answer. We can also use estimating to check our answers, so it is a great skill to learn!

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