Page 70 - Viva

Values and Life Skills

A librarian has arranged books in 5 rows on a shelf. If each row has 28 books, how many

books are there on the shelf?
H T O
Books in one row =

Number of rows = ×

Total books =

Answer: _____________________________________
Do you arrange your books on a shelf at home? Why should we arrange
things in order? Discuss in class.

ACTIVITY

What To Do?
To multiply a 2-digit number with a 1-digit number using Napier strips

What We Need?
Napier strips, white sheet of paper and a pencil Rows 2 8

How To Do? 1 0 2 0 8
• Let’s learn to multiply 28 × 7 with the help of Napier strips. 2 0 1
• Keep the strips of 2 and 8 side by side. 4 6
• Look at row 7. 3 0 6 2 4
1 5 4 0 3
4 6 8 2
• Add the digits along the diagonals as shown. 5 1 0 4 0

1 1 5 6 1 2 4 8
4 6
7 1 5 6
5 + 4 = 9 6 4
Thus, 28 × 7 = 196. 8 1 6 6 4

Use Napier strips given at the end of the book to find the 9 1 7
following products. 2 8 8 2
(a) 35 × 6 (b) 23 × 9 (c) 14 × 4 10 0 0

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