ELI5: Explain Like I'm 5

Normal number

A normal number (sometimes also referred to as a "real number") is any number on the number line. This includes any number that can be written as a fraction, a decimal, or a whole number. Numbers like 5, 1/4, -3.14, and 0 are all normal numbers. Normal numbers are all around us - they're used to measure things like the temperature or how much milk we have left! You can also use normal numbers to add, subtract, multiply and divide. A lot of math is built on normal numbers, so it's important to understand them!