Math vocabulary

Multiple
The result of multiplying a number by a positive integer.
Example: 15, 40, and 95 are all multiples of 5 because they can all be obtained by multiplying an integer by 5.

Factor
A number that divides into another number.
Example: 1, 2, 3, 4, 6, 8, 12, and 24 are all factors of 24 because they divide into 24.

Prime Factor
A prime number that divides into another number.
Example: 2 and 3 are prime factors of 24.

Prime Number
A number with exactly two factors (itself and 1). It only divides by itself and 1.

Integer
A whole number (no decimals), including zero and negative numbers.

Lowest Common Multiple (LCM)
The lowest number that two (or more) numbers will divide into.

Highest Common Factor (HCF)
The highest number that divides into two (or more) other numbers.

Recurring Decimal
A decimal number with a digit (or group of digits) that repeats forever.

Round
Making a number simpler while keeping its value close to what it was.

Decimal Places
The number of digits after the decimal point.
Example: 0.045 is in 3 decimal places.

Significant Figure
The number of digits after the first non-zero digit.
Example: 0.045 and 4500 are written to 2 significant figures.

Negative
A number less than zero.

Power/Index (indices)/Exponent
The power of a number says how many times to use the number in a multiplication. It's written as a small number to the right and above the base number.
Example: 353^535 - 5 is the exponent/index and means 3 is multiplied by itself 5 times.

Base Number
The number that gets multiplied when using an exponent.
Example: In 353^535, 3 is the base number.

Square Root
A square root of a number is a value that, when multiplied by itself, gives the number.
Example: The square root of 16 is 4, as 4×4=164 \times 4 = 164×4=16, written as 16=4\sqrt{16} = 416​=4.

Cube Root
The cube root of a number is a value that, when used in a multiplication three times, gives that number.
Example: The cube root of 64 is 4, as 4×4×4=644 \times 4 \times 4 = 644×4×4=64, written as 643=4\sqrt[3]{64} = 4364​=4.

(nth) Root
The “nth root” used in times in a multiplication gives the original value.
Example: The fifth root of 32 is 2, as 2×2×2×2×2=322 \times 2 \times 2 \times 2 \times 2 = 322×2×2×2×2=32, written as 325=2\sqrt[5]{32} = 2532​=2.