Firstly, press on one of the mini calculators (not the middle one) to start the equation. -There are addition, subtraction, multiplication, division, exponential equations, and square root equations. Secondly, type the first number (only number on square root equations) and tick the mark. Thirdly (skip this step if you are doing a square root equation), type the second number, and tick the mark. Lastly, a window will pop up and tell you the answer to the equation. Just remember not to use letter numbers such as x or y.