SaiBook.us Decimals

Lesson Example Discussion Quiz: Class Homework

Example

Title: Multiplication of Decimals

Grade: 5-a Lesson: S2-L2

Explanation: The best way to understand decimals is by looking at some examples. Take turns and read each example for easy understanding.

Examples:

Find the product of 23.54 \$\times\$ 4.123.

Step 1a

The given numbers are 23.54 and 4.123.

Multiply the numbers as whole numbers by removing the decimal point.

$1a$

Explanation: In this step, we arrange the numbers. Now ignore the decimal point and multiply the two numbers following the regular multiplication method i.e., \$2354 \times 4123 = 9705542\$.

Step 1b

After multiplying two numbers, count the total number of decimal places.

The product will have the same number of decimal places.

$1b$

Explanation: In this step, determine the decimal places in each number by counting the digits to the right of the decimal point. For 23.54, there are 2 decimal places, and for 4.123, there are 3 decimal places.

Therefore, the total decimal places are 5. 23.54 × 4.123 = 97.05542.

Find the product of 45.6 \$\times\$ 24.3.

Step 2a

The given numbers are 45.6 and 24.3.

Multiply the numbers as whole numbers by removing the decimal point.

Explanation: In this step, we arrange the numbers. Now ignore the decimal point and multiply the two numbers following the regular multiplication method i.e., \$456 \times 243 = 1,10,808\$.

Step 2b

After multiplying two numbers, count the total number of decimal places.

The product will have the same number of decimal places.

Explanation: In this step, determine the decimal places in each number by counting the digits to the right of the decimal point. For 45.6, there is 1 decimal place, and for 24.3, there are 2 decimal places.

Therefore, the total decimal places are 45.6 × 24.3 = 1,108.08.