Definition
Sum
A sum is the result of adding two or more values, or the addition expression itself.
What it means
Addition joins amounts or combines changes. The numbers being added are addends; the sum is what the addition makes. In 18 + 7 = 25, 18 and 7 are addends and 25 is the sum.
Remember it
Addends go into an addition; the sum comes out.
Example
A jar has 27 red counters and 16 blue counters. The sum is 27 + 16 = 43 counters.
Watch for
Outside mathematics, “sum” can mean a brief summary or an amount of money. This card owns the addition sense.
Common mix-up
An addend is one value being added; the sum is the result or the whole addition expression.
Exact meaning
A sum is the value obtained by addition. The word can also name an unevaluated addition expression, such as 8 + x.