Page 142 - New Medley 5 Semester 1

2. There are 95 schools in a city. On an average, a school has 1675
students studying in different classes. How many students are there in
the city?

3. On an average, 64 eggs are kept in an egg-tray. A hotel owner buys 35
bundles. Each bundle contains 8 trays. Find the number of eggs that

the owner buys.

4. How many minutes are there in a leap year?

5. Form the largest and the smallest numbers using the digits 1, 4, 0 and
6 only once and find their product.

6. What number do you get when you multiply the predecessor of 531 by
the largest 4-digit number?

Short-cut Tricks in Multiplication

Z Z Multiplication by multiples of 10s, 100s, 1000s, etc.

To multiply a number, say 246, by the numbers like 20, 400, 6000, etc.,
we first multiply the given digits 2, 4, 6 of the numbers respectively

and put as many zeros in the product as present in the multiplier.

i.e., 246 × 20 = 4920 246 × 400 = 98400 246 × 6000 = 1476000

( 246 × 2 = 492) ( 246 × 4 = 984) ( 246 × 6 = 1476)

Z Z Multiplication by numbers 5, 25 and 50

Consider the following division facts:

10 ÷ 2 = 5 100 ÷ 4 = 25 100 ÷ 2 = 50

To multiply a number by 5, put one zero to the right of the number
and divide it by 2.

Examples: 64 × 5 = 640 ÷ 2 = 320, 325 × 5 = 3250 ÷ 2 = 1625, etc.

To multiply a number by 25, put two zeros to the right of the number
and divide it by 4.

Examples: 268 × 25 = 26800 ÷ 4 = 6700, 4372 × 25
= 437200 ÷ 4 = 109300, etc.

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