Kilograms and grams

In your book, Maths Mela (Chapter 8), Rita and Shabnam go to the market. The vegetable seller puts a pumpkin on one pan of a balance and a 1 kg weight on the other. The pans stay level, so the pumpkin weighs 1 kg. Then he cuts the pumpkin into two equal halves, and the halves balance each other. What does each half weigh? We need to know about grams.

1 kilogram is the same as 1000 grams. We write kg for kilogram and g for gram: 1 kg = 1000 g. A 1 kg packet of daal balances 2 packets of 500 g, because 500 g + 500 g = 1000 g. So 500 g is half a kilogram: 500 g = 1/2 kg. Each half of the pumpkin weighs 500 g.

4 packets of 250 g also balance 1 kg, because 250 g + 250 g + 250 g + 250 g = 1000 g. So 250 g is a quarter of a kilogram: 250 g = 1/4 kg. And 10 packets of 100 g make 1000 g, which is 1 kg.

How many 250 g packets balance one 500 g packet? Two, because 250 g + 250 g = 500 g. So 250 g is half of 500 g.