| A | B |
|---|
| Remainder | the number less than the divisor that remains after the division is complete. |
| Estimate | to find a number that is close to an exact number. |
| Rounding | Replacing one number with another number that tell about how many. |
| Front-end estimation | A way to estimate a sum by adding the first digit of each addend and adjusting the result based on the remaining digits. |
| Clustering | when values are close together an average value is found. |
| Friendly numbers | numbers that are easy to use to calculate answers. |
| Additive comparison | the difference between two quantities. |
| Multiplicative comparison | focus on comparing two quantities by showing that one quantity is a specified number of times larger or smaller than the other. |
| Addend | a number added to find a sum. |
| Sum | The answer to an addition problem. |
