Final answer:
When you adjust one number and change another number in the problem to make a computation easier, you use compatible numbers.
Step-by-step explanation:
When you adjust one number and change another number in the problem to make a computation easier, you use compatible numbers.
Compatible numbers are numbers that are easy to work with mentally and give a similar result to the original problem. For example, if you have the problem 245 + 127, you can adjust the numbers to 250 + 125, which are compatible numbers that make the computation easier.
Using compatible numbers is a helpful strategy to simplify calculations and get a reasonably accurate estimate of the answer without needing to perform complex calculations.