Multiplying by 9 cool ways

Multiplying by 9 cool ways
  • Currently 4.0/5 Stars.
7108 views, 6 ratings - 00:10:25
Taught by YourMathGal

Meets NCTM Standards:

More free YouTube videos by Julie Harland are organized at http://yourmathgal.com
This video shows you easy ways to multiply single digits by 9, and larger numbers when all the digits are the same, like 88888 x 9...really easy and fun to do!

  • Meteor Multiplication - Game from Math Game Time: Meteor Multiplication is a single-player game assisting students in learning multiplication. Large meteors with multiplication problems move in toward a large star station in the center of the screen. The student must fire at meteor with the correct answer to the given problem.
  • How do you multiply a single-digit number by 9 with your fingers?
  • What are some cool ways of multiplying by 9?
  • How do you multiply 9 times 3 with your fingers?
  • How do you multiply 9 times 6 with your fingers?
  • What are some patterns that occur when multiplying by 9?
  • How do you multiply large numbers by 9?
  • How do you multiply 9 times 33, 44, 77, or 88 without a calculator?
  • How do you multiply 9 times 3333, 444, 666666, or 88888 without a calculator?
This lesson explains a very useful tactic that many kids learn in elementary school, how to multiply by 9 with your fingers. Also, different methods of multiplying by 9 are shown that do not involve using your fingers. One pattern that is pointed out is that the product of 9 times a single digit number gives a first digit of one less than the number you are multiplying by and a second digit that is 9 minus the first digit. Also, multiplying 9 by a multi-digit number where all digits are the same is explained.
  • Currently 3.0/5 Stars.
Reviewed by MathVids Staff on July 19, 2009.
very knowledgeable
  • Currently 5.0/5 Stars.
Reviewed by ktoluv on September 26, 2009.
It is very knoledgeable, but it doesn't tell that how to calculate 9 x any 3 different nos. (eg.108).
  • Currently 3.0/5 Stars.
Reviewed by jenmaths on August 07, 2010.
this really helped me learn my math teacher couldn't teach that
  • Currently 5.0/5 Stars.
Reviewed by student 101 on September 03, 2010.
 
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