Click on the respective class icon for the list of formulas. Absorb the formulas via different channels. Type a plus sign then use your pointer to select C2 to enter the second cell reference into the formula.
So here in this page.
To get formula list of mathematics for class 6 7 8 9 10 11 and 12 click on respective classes menu. This time can be gradually reduced 25 minutes 20 minutes 15 minutes etc as you start having the formulas imprinted in your mind. Allocate a specific time during the day for formula revision- 30 minutes per day. Use those mnemonic devices to try memorize formulas you have a hard time with.