Of those who say nothing, few are silent.
 - Thomas Neiel

Grade 3

Theory: 

Estimating a sum by rounding

A quick way to estimate the sum of two numbers is to round each number and then add the rounded numbers. This probably won't be the exact answer but it may be close enough for some purposes.

How to Estimate a sum by rounding?

Round each number that will be added

Add the rounded numbers

Some uses of rounding are:

Checking to see if you have about enough money to buy what you want.

Getting a rough idea of the correct answer to a problem.

Solutions from the Previous Issue:

Calculate:

1.       

Solution:

2.       

Solution:

606240

3.       

Solution:

4.       

        Solution:

5.       

        Solution:

        92 + 64 =156

Proposed Exercises:

Calculate:

1.        50 m + 30 m + 120 m =

2.        36 kg + 72 kg + 48 kg =

3.        324 cm + 256 cm =

4.        70 l + 20 l + 540 l =

5.        728 m – 324 m =