1 / 8

Understanding Divisibility Rules: A Guide to Mental Math

This guide explores the concept of divisibility through mental math techniques. Learn how to determine if a number is divisible by 2, 3, 4, 5, 6, 9, or 10 using simple rules and calculations. Discover examples, such as whether 56 is divisible by 4 or 64 by 6, along with methods for calculating divisibility based on the sum of a number's digits. You'll also find practice problems to test and improve your skills. Master these divisibility rules to enhance your mathematical abilities and confidence.

halee-atkins
Télécharger la présentation

Understanding Divisibility Rules: A Guide to Mental Math

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. 4.1 Divisibility and Mental Math

  2. Mental Math • Is 56 divisible by 7? Think! • 56 = 8 x 7 • Is 56 divisible by 4? Think! • 56 = 8 x 7, and 4 x 2 = 8, 56 is divisible by 4.

  3. Mental Math • Is 64 divisible by 6? • No • Is 93 divisible by 3? • Yes

  4. Divisibility Rules • A whole number is divisible by • 2, if the number ends in 0, 2, 4, 6, or 8. • 3, if the sum of the number’s digits is divisible by 3. • 5, if the number ends in 0 or 5 • 9, if the sum of the number’s digits is divisible by 9 • 10, if the number ends in 0.

  5. Divisibility by 2, 5, 10 • Ends in … • Test each number for divisibility by 2, 5, 10 • 150 • 1,021 • 2,112 • 65 • 100

  6. Divisibility by 3 • Sum of number’s digits is divisible by 3 • 715 • 7 + 1 + 5 = 13 • 13 is not divisible by 3 • 150 • 1 + 5 + 0 = 6 • 6 is divisible by 3

  7. Divisibility by 9 • sum of number’s digits is divisible by 9 • 163 • 1 + 6 + 3 = 10 • 10 is not divisible by 9 • 126 • 1 + 2 + 6 = 9 • 9 is divisible by 9

  8. Try it! • Test each number for divisibility of 2, 3, 5, 9, and 10 • 60 • 48 • 81

More Related