| A | B |
|---|
| Sum | the answer to an addition problem |
| Difference | the answer to a subtraction problem |
| Round | to replace a number with another number that tells about how many or how much |
| expression | a phrase that uses numbers and operation signs but no equal sign |
| variable | a letter or symbol that can stand for any unknown number |
| pictograph | a graph that uses pictures to show and compare information |
| period | a goup of three digits in a number |
| digit | one of ten symbols used to write numbers |
| benchmark | a known number of things that helps you estimate |
| place value | the value of a digit in a number |
