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