Page 78 - Touchpad Mathematics_Ver1.0_C4

example 1. Multiply 7 by 8.

Solution:

• Touch the fingers marked with 7 and 8.
7 8
• Count the fingers up to the touched fingers on both
hands and get the digit in the tens place. Here the

sum of the fingers on both hands is 2 (left hand) + 7 x 8
3 (right hand) = 5

• Multiply the fingers above the touched fingers of both hands. 3 × 2 = 6
Hence, 7 × 8 = 56.

example 2. Multiply 8 by 8.

Solution:
• Touch the fingers marked with 8.
8 8
• Count the fingers up to the touched fingers on both
hands and get the digit in the tens place. Here the

sum of the fingers on both hands is 3 + 3 = 6

• Multiply the fingers above the touched fingers of both hands. 2 × 2 = 4
Hence, 8 × 8 = 64.

MulTipliCATioN By A 1-DigiT NuMBer

We use multiplication tables to find the products.
Multiplication of a 2- and 3-digit Number by a 1-digit Number

(Without regrouping)

example 1. Multiply 12 by 3.
Solution.

Step 1. Multiply the ones. Step 2. Multiply the tens.

T O T O

1 2 1 2
× 3 × 3

6 3 6 Keep in Mind

2 × 3 = 6 ones 1 × 3 = 3 tens 0 times a number is
always 0.
So, 12 × 3 = 36.

76 Mathematics 3