Essential Math Glossary
Understanding the vocabulary of mathematics is the first step to mastering the concepts. Here are key terms students will encounter in Grades 4 through 7.
Place Value
The numerical value that a digit has by virtue of its position in a number. For example, in the number 4,562, the 5 represents 500 because it is in the hundreds place.
Decimal
A number that uses a decimal point to show a value less than one. Decimals are used to represent fractions based on powers of ten, such as 0.5 (which equals one half).
Fraction
A way to represent a part of a whole. It consists of a numerator (the top number) and a denominator (the bottom number), such as 3/4.
Algebra
A branch of mathematics that uses letters or symbols (variables) to represent unknown numbers in equations and formulas. For example, x + 5 = 10.
Ratio
A comparison of two quantities. If a classroom has 10 boys and 15 girls, the ratio of boys to girls is 10:15, which simplifies to 2:3.
Perimeter
The total distance around the outside edge of a 2D shape. For a rectangle, it is calculated as 2 × (Length + Width).
Area
The amount of space inside the boundary of a flat, 2D object. For a rectangle, Area = Length × Width.
Volume
The amount of 3D space taken up by an object, measured in cubic units. For a rectangular prism, Volume = Length × Width × Height.
Integer
A whole number that can be positive, negative, or zero, but does not contain a fractional or decimal part. Examples include -3, 0, and 42.
Percent
A ratio or fraction that compares a number to 100. The word "percent" literally means "per hundred," so 25% is equal to 25/100 or 0.25.