Rounding numbers or compatible numbers are usually use to be able to calculate a certain number easier and faster.
For the given equation, we have 302 + 412 which is equals to 714 not 577.
Now, let’s look for a rounding or compatible number to estimate the sum.
=> 302, we have 300 as rounding number or compatible numbers
=> 412, we can have 415 as rounding numbers
=> 300 + 415 = 715.
The exact answer is 714 and our estimated is 715.