With this trick, you will be able to multiply any two numbers from 11 to 19 in your head quickly, without the use of a calculator. Just follow four simple steps.I will assume that you know your multiplication...
First understand the derivation of the formula. Summarise all the formulaes on a paper and carry it where ever you go in the pocket. You need not open and learn them. Just make sure you see them when ever you get sometime .
Even though you did a full length preparation and revised all chapters just a day before exam you will be confused if everything is memorised or not. In such situation build confidence rather than subject...