1 / 7

Doubling & Halving with Multiplication

Doubling & Halving with Multiplication. Doubling and halving works because of the relationship between multiplication and division. Since multiplication and division are opposites, we can multiply one factor by 2 and divide the other factor by 2 and the product does not change.

brenden-duncan
Télécharger la présentation

Doubling & Halving with Multiplication

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. Doubling & Halving with Multiplication

  2. Doubling and halving works because of the relationship between multiplication and division. Since multiplication and division are opposites, we can multiply one factor by 2 and divide the other factor by 2 and the product does not change.

  3. This method of multiplication works well with some numbers. Numbers that are multiples of 5 and 10 work well. Since it is more difficult to compute with fractions and decimals, it works best to take half of an even number. With some experience, students soon find which numbers work nicely with this method.

  4. 64 x 25 = ? 64 x 25 I can easily take half of 64 and double 25. 32 x 50 I can easily take half of 32 and double 50. 16 x 100 I can easily find this product! 16 x 100 = 1600 “COOL”

  5. Try one on your own… Choose a problem from these: 33 x 55 45 x 36 5 x 148

  6. 10 x 74 = 740 Did you choose this? 5 x 148 5 x 148 I can easily double 5. I can take half of 148. x 10 74 Now it’s easy with 10. How did you do?

  7. Doubling and Halving This method of multiplying supports mental math. This method also supports the properties of multiplication and division. Students feel SO powerful when they can use this!

More Related