Unlucky for sum, but here is a unique method to learn your 13 times table!!

Unlucky for sum, but here is a unique method to learn your 13 times table!!

This is a unique method to write your 13 times tables and works for any number of tables. Get your pupils to investigate that it does work and why it does.

So in the example of the 13 times tables write the tables of 1 and 3 next to each other as follows. Make note of the comments in the brackets as they are important in defining your list!

1    3 (13)
2   6 (26)
3   9 (39)
4   12 (The 1 is added to the 4 to become 52)
5   15 (The 1 is added to the 4 to become 65)
6   18 (78)
7   21 (91)
8   24 (104)
9   27 (117)
10  30 (130)

Enjoy!! There are tops for the 14 times table on the next page.

Posted in Lesson plenary, Lesson starters, Mathematics Tagged with: ,
5 comments on “Unlucky for sum, but here is a unique method to learn your 13 times table!!
  1. tim campbell says:

    this works for any 11-19 times table.

    for example, replace the multiples of 3 with multiples of 6 and you have the 16 times table.

  2. Kyle Savage says:

    Why was something like this not introduced when I went through elementary school? (or middle school as far as that goes). This is a great alternative to using simple times tables and allows for exploration and description as to why those multiplication steps actually work.

  3. Ralph says:

    Thanks. Kids will enjoy this ‘new’ method for mental.

  4. Peter Cincotta says:

    Thanks for sharing this trick to learning the 13 times table. I had never seen it before; so I always love to learn new things!
    Please don’t misunderstand this comment, but I am always concerned about teaching students “tricks” that have no connection to actual math processes. Still, it is interesting that this works. Maybe there is a mathematical proof. I quickly checked this process for the 14 and the 17 times tables and (sure enough) it works for them too. I checked it for the 29 times table and it worked again.
    I would say that it would be an interesting problem to ask students to prove why this trick works. The formula appears to be: 13x=10[x+(the tens digit of 3x)]+(the units digit of 3x). And then prove it for the general case of any two-digit number.
    Thank you for sparking my interest!

Leave a Reply

Your email address will not be published. Required fields are marked *

*

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>