Addition And Subtraction: Math Terms Explained
Plain-language definitions of every addition and subtraction term your child meets in school, each with kid-friendly explanations, worked examples, and common mistakes to watch for.
Addend
An addend is a number that is being added to another number in an addition problem, and the result of adding the addends is called the sum.
Adding within 100
Adding within 100 is adding numbers so that the answer is any whole number from 0 to 100, using place value, counting, and other strategies, with or without regrouping tens and ones.
Addition
Addition is the operation of putting numbers or amounts together to find a total, often described as getting more, combining groups, or counting on.
Counting on
Counting on is a mental math strategy that starts with a known number and counts forward.
Doubles facts
Doubles facts are basic math facts where the same number is added to itself, like 3 + 3 or 7 + 7, and the results of these facts are used as quick mental anchors for addition, subtraction, and early multiplication.
Fact family
A fact family is a set of related addition and subtraction number sentences that use the same three numbers and show how they are connected.
Mental math
Mental math is solving math problems in your head without writing anything down or using a calculator, often by using quick strategies with place value to get exact answers or good estimates.
Minuend
A minuend is the starting number in a subtraction problem, the amount you begin with before something is taken away to find the difference.
Number bond
A number bond is a picture that shows how two or more parts fit together to make a whole number, helping children see and understand addition and subtraction relationships.
Number sentence
A number sentence is a math statement that uses numbers, operation symbols (like +, -, ×, ÷), and an equal or comparison sign to show that something is true or to be solved.
Partial sums
Partial sums are a way to add numbers by breaking them into place values, adding each place separately, then adding those smaller answers to get the total.
Properties of addition
Properties of addition are special rules that show how numbers can be added in different orders or groupings without changing the total, including the commutative property, associative property, and identity property.
Regrouping
Regrouping is a place-value strategy in addition and subtraction where equal amounts are traded between ones, tens, hundreds, and other places so the total value stays the same but is easier to work with.
Subtracting across zeros
Subtracting across zeros is a kind of subtraction where the top number has one or more 0 digits, and you need to regroup through those zeros to subtract correctly using place value.
Subtraction
Subtraction is a math operation that finds how much is left or how far apart two numbers are, by taking away, taking apart, or comparing quantities.
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