Estimating is the ability to solve number problems in quickly and/or in your head. We estimate a lot in our daily lives.
The key skill to estimate is rounding.
When rounding remember:
1. Identify the digit to be rounded and identify the digit to the right of it.
2. If the digit is 5,6,7,8, or 9 then change the digit to be rounded, one number higher.
If the digit is 4, 3, 2, 1 or 0 then do not change the digit to be rounded-- it stays the same.
3. All other digits should be changed to zero.
Example
2,564 is rounded to 3,000
2,564 round to the last digit
2 is the digit to be rounded
5 is the digit to the right.
It is 5 therefore 2 changes to 3