Shopping lists

In your book, Maths Mela (Chapter 7), Daisy and Lou are going on a school trip. First they go shopping with their mother. Sapan Dada sells fruits and vegetables from his cart. His price list gives the cost of 1 kg: custard apple ₹45, beans ₹95, radish ₹23, onion ₹32, potato ₹37, yam ₹45, sapota ₹70, papaya ₹65 and banana ₹55.

To find the cost of 2 kg, we add the cost of 1 kg twice. 1 kg of beans costs ₹95, so 2 kg of beans cost ₹95 + ₹95 = ₹190.

To find the cost of two different things, we add their costs. 1 kg of onion and 1 kg of potato cost ₹32 + ₹37 = ₹69. What about 2 kg of onion and 2 kg of potato? That is ₹64 + ₹74 = ₹138. Look: ₹138 is double ₹69. Twice as much of each thing costs twice as much money.

We can also work the other way. Their mother spends ₹163. What could she have bought? 1 kg each of beans, radish and yam costs ₹95 + ₹23 + ₹45 = ₹163. That is one answer. There are others too, because some things cost the same.