823-242 use rounding or compatible numbers to estimate the difference

We have to use rounding or compatible numbers to estimate the difference of 823 and 242.

Since, a quick way to estimate the difference between two numbers is to round each number and then subtract the rounded numbers.

Therefore, rounding the number 823 to the nearest tens = 820

Rounding the number 242 to the nearest tens = 240

The difference between the estimated numbers

= 820 - 240

= 580

Therefore, the estimated difference is 580.