Math Cipher - Addition / Subtraction The NEW math products provide an enhanced approach to Flash Cards, taking mental math to a new level. Throughout the day we are constantly using basic, multi function formulas without realising it. Math Cipher introduces children to this step-by-step process in a unique, fun, and self correcting way. Each set comes with 24 cards and 80 challenges that range from easy to hard. STEP 1: Turn the wheel to cover one of the three numbers in the red filter. STEP 2: Make an equation using the numbers (in coloured cicrles) and functions ( + , - ) to match the number you have covered in red. STEP 3: Turn the wheel clockwise to reveal the correct answer magically!