Working from a bar graph

In your book, Maths Mela (Chapter 15, Data Through Pictures), Rani lives in a residential school. The dining hall shows how much food is wasted, and how many children that food could have fed. Rani was shocked to see the data. The school's notice says: take all you can eat, eat all you take.

The book shows a bar graph of the food wasted on five weekdays. Each bar is one day's food item, and its height is the kilograms (kg) wasted: Sandwich on Monday, 5 kg. Paratha on Tuesday, 6 kg. Khichdi on Wednesday, 8 kg. Puri-Sabzi on Thursday, 7 kg. Idli-Sambar on Friday, 4 kg.

The tallest bar is khichdi (8 kg), so khichdi had the most wastage. The shortest bar is idli-sambar (4 kg), so it had the least. To find the total, add all the bars: 5 + 6 + 8 + 7 + 4 = 30 kg.

Some questions need one more step. If 1 kg of food can feed 3 children, then 30 kg could feed 30 × 3 = 90 children. We can also compare days: Friday (4 kg) had less wastage than Monday (5 kg), and Thursday (7 kg) had less than Wednesday (8 kg).