How to Estimate.

Before doing the actual calculation you should think:

"How do I go about making this estimate?"

 Different numbers need different methods:

Example:

• 550 + 298: 298 is nearly 300 so an estimate is 550+300 = 850
• 550 + 248: 550+250  = 800

But how do you know what to do? Lots of Practice!

                            Tips and Tricks

Here is a  method you might like to use:

Round the numbers up or down before the calculation.

Example: 206 × 390.

Because 206 is nearly 200, and 390 is nearly 400, the answer will be close to

200 × 400 = 80.000

http://www.mathsisfun.com/numbers/estimation.html