The Class 7 Maths Chapter 13 simple interest contains various topics about simple interest. First of all, one should understand what is principal. The principal is the total amount of money invested or borrowed, not including any interest or dividends. For instance, Mr R borrowed 500 rupees from Mr X. Here, the loan principal is 500 rupees. Secondly, one should know about interest. In simple terms, interest is nothing but the money paid/received for the use or investment of money. For example, Sid invests 50,000 rupees and receives 500 rupees every year as interest.
Additionally, this chapter also deals with the amount and how to calculate it. An amount is nothing but total money paid back at the end of the period for which it was borrowed or the investor's total money at the end of a given investment period. The formula for this is,
Amount (A) = Principal (P) + Interest (I)
SI = (P * R * T) / 100
SI = simple interest
P = principal
R = rate of interest (in %)
T = time duration (in years)
So, the chapter teaches the students to calculate simple interest, rate of interest, time of invertest and the total amount.