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numbers added in an addition problem


any process for solving a mathematical problem

commutative property of addition

changing the order of addends does not change their sum (a + b = b + a)

identity property of addition

the sum of any number and 0 is equal to the initial number (a + 0 = a)


the result of addition

ordinal numbers

numbers that describe position or order (first, second . . .)


the result of subtraction

fact family

a group of three numbers related by addition & subtraction or by multiplication & division

inverse operations

operations that "undo" one another


a number sentence that uses the symbol = to show that two quantities are equal


the top (or largest) number in a subtraction problem


the bottom (or smaller) number in a subtraction problem

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