Rounding Numbers

Rounding Numbers

By Yashod Kalingage

Introduction

Rounding numbers is basically rounding a number to the nearest 10, 100, 1000, and so on. In this lesson, we will be rounding numbers to the nearest 10. Let's begin with a short poem on the next slide.

" Find the number.
Look right next door.
Five or more, raise the score.
Four or less, let it rest." 

​Meaning of The Poem

• What do you think the poem means?

• The poem means that you first have to locate the number. If rounding to the nearest 10, you must look at the ten's digit.

• Then, you must look at the number on the right.

• If the number on the right, the one's digit, is 5 or more, you must turn all digits that come after the tens digit into 0's and increase the ten's digit by one.

• If the number on the right is 4 or lower, the only difference is that you keep the ten's digit the same.

​Important Facts about Rounding

• If the number is a multiple of 10, the number will be the same when it is rounded to the nearest 10.

• Rounding can be applied to whole numbers, decimals, and fractions.

• Rounding numbers is mostly used to simplify data including many numbers.

Activity Time!

Multiple Choice

Q1

Round 37 to the nearest 10.

• 30
• 35

• 20

• 40

Multiple Choice

Q2

Round 45 to the nearest 10.

• 50
• 60
• 45

• 40

Multiple Choice

Q3

Round 70 to the nearest 10.

• 60
• 75
• 80
• 70

Thank You!