Page 562
Math Terms
Addition (+) is combining numbers to get a total, which is called a sum. The sum of 3 plus 5 is 8; 3 + 5 = 8.
An angle is made when two rays (lines) share a common endpoint. An angle is measured in degrees.


Area is the total surface within a closed figure (circle, square, etc.). The area of a rectangle is figured by multiplying the length by the width. Area is measured in square units such as square inches or square feet.
The average is found by adding a group of numbers together and then dividing that sum by the number of separate numbers (addends). The average of 7, 8, and 9 is 8, because 7 + 8 + 9 = 24, and 24 ÷ 3 (numbers) = 8. This is also called the mathematical mean.