Square numbers ending in 5

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Taught by YourMathGal
  • Currently 3.0/5 Stars.
1927 views | 1 rating
Meets NCTM Standards:
Errors in this video:

At about the 11:42 mark, the teacher says we've got the hundreds, tens, and thousands; she should have said hundreds, tens, and ones.

Lesson Description:

Shows an easy way to square numbers ending in 5 such as 65 times 65, etc. Shows an alternate way to multiply decimals using a lattice.

More free YouTube videos by Julie Harland are organized at http://yourmathgal.com

Questions answered by this video:
  • What is a short way to square numbers ending with a 5?
  • What does 15^2 equal?
  • What does 25^2 equal?
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  • What does 55^2 equal?
  • What does 65^2 equal?
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  • What does 115^2 equal?
  • What does 205^2 equal?
  • Staff Review

    • Currently 3.0/5 Stars.
    In this lesson, the teacher shows a cool way to square numbers that have a 5 as their last digit. At the end, she explains why this method works.