1) digit – the symbols 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 used to write numbers
2) whole numbers – the set of counting numbers and zero: 0, 1, 2, 3, 4 . . .
3) place value – the value determined by the position of a digit in a number
4) symbol – a printed mark used to represent an operation or abstract idea
5) sum – the answer to an addition problem
6) difference – the answer to a subtraction problem
7) round – to estimate a number to the nearest ten, hundred, thousand, etc.
8) estimate – noun: an answer that is close to the exact answer
verb: to guess about how much or how many
9) standard form-