Estimation can be used to verify results. We will use estimation to find the sum and differences of fractions with like denominators.

Simple Steps to Estimating

• Find whatever place value you are looking to estimate to
  and
  look at the digit to the right.
  

• If the digit to the right is "5 or higher"
  the place value INCREASES by 1.
  

• If the digit to the right IS NOT "5 or higher"
  the place value STAYS as it is.
  

• All the rest of the numbers to the right of the place value become ZEROS.

Estimating sums of fractions with like denominators

	Estimation: 2 + 2 = 4
equals 4 Estimation was used to verify results.

You can round numbers to tell about how much or about how many. Rounding can be used to verify results.

To round numbers:

• Find the place you are rounding to.

• Look at the digit to its right.
  
  If the digit to the right of the place one is rounding to is                             less than 5, round down    ;
                             if it is 5 or greater, round up    .

Example 1: Round to the nearest ten: 25, 52, 78

25   5 = 5 round up. 25 = 30	52  2< 5 round down. 52 = 50	78  8> 5 round up. 78 = 80
Same is true for fractions. If the fraction equals or is greater than 1/2 round up. If the fraction is less than 1/2 round down.
round up		round down

Estimating differences of fractions with like denominators

Remember:

~ If the number to the right
of the place value you're looking to estimate
is "5 or higher",
increase the place value number by 1.

~ If the number to the right
of the place value you're looking to estimate
is NOT "5 or higher",
the place value number STAYS
as it is.

Let's Practice