Estimation gives you an idea of what the actual answer is. Learning to estimate can help you add large numbers quickly.

Example:

536923
+ 32563
	Estimate

Step 1:   Identify which place value you need to round to.
The largest place value of the number with the fewest digits is the place value to round to.

536923 has 6 digits and 32563 has 5 digits.
32563 has fewer digits and its largest place value is the ten-thousands.

Step 2:   Round the numbers to the correct place value found in Step 1.
We're rounding to the nearest ten-thousands.

536923 rounds to 540000.
  32563 rounds to   30000.

Step 3:   Add the rounded numbers to get the estimated sum.

540000

+ 30000

570000

The answer is