Quick explanation: We use numbers and math every day. Let us review some of the common terms we utilize when we do simple math, such as: suma -addition, and resta -subtraction.

+ más - plus
2 + 3 dos más tres
- menos - minus
10 - 5 diez menos cinco
= igual a - equals
8 + 1 = 9 ocho más uno igual a nueve
Do the math!

Long Explanation:
In addition to the terms previously mentioned we also use other common terms (while shopping, planning a budget, measuring, etc.) Here are a few examples:
Multiplication
* por - times
7 * 4 siete porcuatro
Division
/ dividido entre - divided by
12 / 6 doce dividido entre seis
Decimals
10.5 diez punto cinco
Percentages
25% veinticinco por ciento
Fractions
Just as in English, when we say fractions in Spanish we say the numerator as a cardinal number and the denominator as an ordinal number (always adding an -s).
3/4 tres cuartos
10/5 diez quintos
There is an exception when the denominator is "2". We say medio -half.
1/2 medio -half.

Ordinal Numbers