Learning the 9’s Times Tables.


Teaching the 9’s tables can be very challenging for some reason.   However, there are a few tricks that suddenly make learning the 9’s tables easy.

 

Now the first method many people have used is the finger method.  That is ok but can be a little slow when the student is trying to work on speed.  However, it allows your child some initial success and overcome the discouragement of frequent wrong answers.    Too many failures can make the multiplication tables feel like a insurmountable mountain to them.  So, judge for yourself if you feel your child would benefit from the transition from finger method to another method I call the subtraction method.  The subtraction method just requires some simple subtraction, but becomes very fast quickly.  Both, however, only work form 1-9, keep reading though for 9×10, 11 and 9×12 below.

To understand the finger method, if you are not already familiar, I will outline it now:

Have your child look at the palms of their hands like this:

 

Finger rule 9 times tables

Finger rule 9 times tables

 

Now, for 9 x any number have your child put down the finger that is being multiplied by 9, so in this example for 9×7 they just put down the 7th finger and get this:

9x7 finger rule

9×7 finger rule

 

For 9 x 4 it would look like this:

Finger rule of 9's tables

Finger rule of 9’s tables

This works from 9×1 up to 9 x 10.

 

For the subtraction rule, it is a matter of simply realizing that every number x 9 always adds up to 9:

learning 9 tables, always adds up to 9

learning 9 tables, always adds up to 9

Once that is realized you can quickly teach your child that for any number of to 9, when multiplied by 9, subtract one and then figure out how many more to get to 9.  That is your answer.  This is how it would work for 9×7:

9x7 subtraction rule

9×7 subtraction rule

After a possible slow start they will be able to quickly rattle off the answers.

For 9×10, your child should already know the 10 rule (which we taught before the 9 rule in the app), so that is easy 9×10=90.  To help them remember the 10 rule if you haven’t already we describe it like Cheerios, here is a 10×7 snapshot from the video in the app teaching 10’s:

10 likes to hand out 0's think breakfast cereal!

10 likes to hand out 0’s think breakfast cereal!

Now for the 9×11, teaching your child the 11 rule first is helpful. That is why in the app they learn that rule first, but just to review, the 11 rule is easy: 11 acts just like a mirror, so the answer is 99:

Teaching 9x11

Teaching 9×11

Finally, the only one that requires actual memorization is 9×12, it may sound crazy if you haven’t reviewed the mnemonic system but in short the character for 9 is pie, and the character they learned for 12 is Tin. Then using the time tested major memory system of turning numbers into sounds (aDheSiVe=108) we get a cartoon like these snapshots:

Snapshot from video in Fun Times Tables! app

Snapshot from video in Fun Times Tables! app

 

Snapshot from video in Fun Times Tables! app

Snapshot from video in Fun Times Tables! app

 

It may sound complicated, but kids quickly associate the adhesive with 108 and then they know the answer to this last item of 9×12 and now they know all of the 9’s multiplication tables.

After this is it is review, review, review.  FOCUSED review is always better, make sure you spend more time on the ones your child is getting wrong.  That is why we did not use pure randomization in quiz mode of Fun Times Tables! but instead we have the app learn where child is slower or wrong and quiz those questions more often.  As a parent you can do that a lot easier than it was to code of course!

I hope that helps!  what tricks have you found helpful to teach the 9’s.  Please post and share!

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