Multiplication problems

In your book, Maths Mela (Chapter 6, The Dairy Farm), we use multiplication to solve real problems. First find the equal groups: how many groups are there, and how many are in each? A school auditorium has 35 rows with 42 seats in each row, so it has 35 × 42 seats. 35 × 40 = 1,400 and 35 × 2 = 70, so there are 1,400 + 70 = 1,470 seats.

Gollappa has 29 cows, and each gives 5 litres of milk a day: 29 × 5. Use a nearby number: 30 × 5 = 150, minus one cow's 5 litres, is 145 litres. A family makes 35 kg of kitchen waste in one month, so in 12 months it makes 12 × 35 = 420 kg.

Some problems need more than one step. Anjali buys 15 bulbs at ₹25 each and 12 tube lights at ₹34 each from Sudha Electricals. Step 1, the bulbs: 15 × 25 = ₹375. Step 2, the tube lights: 12 × 34 = ₹408. Step 3, add: ₹375 + ₹408 = ₹783. That is what Anjali gives the shopkeeper.

Mala goes to a book exhibition. The shop sells 3 books for ₹150, and she buys 18 books. 18 books make 6 sets of 3, so they cost 6 × ₹150 = ₹900. After buying them she still has ₹20 left, so at the beginning she had ₹900 + ₹20 = ₹920.

In a test match against the West Indies, the Indian team hit twenty-four 4s and eighteen 6s. Runs from 4s: 24 × 4 = 96. Runs from 6s: 18 × 6 = 108.