How do you make maths interesting? There are many ways, but one metaphor that has been fairly effective with my students is money. They come from backgrounds where resources are limited, so something related to increasing wealth (or protecting oneself from losing it to a thug) piques their curiosity.
They want to know if they should borrow — if so, from who? They want to understand the difference between saving a hundred rupees under their pillow vs depositing it in a bank. They want to know whether they are even eligible (or qualified) to open an account in the bank… Some of my students wonder whether it makes a difference for someone to save if he/she has so little?
Fortunately, compounding comes to rescue. When you help them work out how 10,000 rupees grow in to 41,770 in 15 years at 10% interest (roughly the rate offered in Indian banks currently), they look at the black board with interest. Their eyes light up much more, when asked, how would it feel if the tables were turned.. that is, if someone had lent them or their parents money, and was compounding at a high rate? How a loan of 10,000 rupees can become a loan of over 20,000 rupees in a matter of just a few years? My students probably know of a friend or family member, who was duped in to borrowing money at a high rate of interest, and later found themselves unable even to make the interest payment.
The kids now know that a small regular saving can grow to a large one through compounding over time. They want to start saving early, even if it’s just a few rupees every week. They even encourage their parents to register for bank accounts. Yaseen, one of our young students, helped his illiterate father fill out the bank application and complete all formalities that were required to get their accounts registered.
P.S. — As bonus, I learned that simple interest is called सामान्य ब्याज in Hindi. And compound interest? You guessed it right (;)) : चक्रवृद्धि ब्याज.