According to me ,
step 1: understand the question first
step 2: write all the given information
step 3: understand what to find
step 4 : write the formula wherever necessary
step 5 finally try to solve the question
the girl went to the shop and she buy 4 pens of Rs.3 each, 2 notebooks of Rs 10 each. and she paid Rs. 50 to the shop keeper then how much she will get her balance.
1 pen = Rs.3
4 pens = Rs 4x3 = 12
1 notebook = Rs.10
2 notebooks = 10 x 2 = 20
so she have to pay = 12 + 20 = 32 Rs.
but she paid Rs. 50
so, she has to get balance = Rs. 50 - 32 = Rs.18
(I gave simple sum to understand)