SaiBook.us Decimals

Lesson Example Discussion Quiz: Class Homework

Example

Title: Decimal Addition

Grade: 4-a Lesson: S1-L1

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 sum of \$37.5 + 47.9\$

Step 1a

Add the both numbers as whole numbers.

$1a$

Explanation: In this step,we arrange the numbers.

Step 1b

Write down the numbers, one under the other, with the decimal points lined up.

$1b$

Explanation: We can add decimals the same way we add whole numbers. We just make sure that digits of the same value are lined up underneath each other.

First, write the larger number above the smaller number, making sure to line up the decimal points.
Add another decimal point on the bottom row. If you need to, label the columns to show the place value of each.
Then we can find the sum, just like we do with whole numbers.

Step 1c

After adding two numbers, count the total number of decimal places in both. The result will have the same number of decimal places.

$1c$

Explanation: In this step, determine the decimal places in each number by counting the digits to the right of the decimal point. 36.5, there is one decimal place, and in 47.9, there is also 1. Therefore, the total decimal places are 2. 36.5 + 47.9 = 85.4