Multiplication Mechanics

Not everybody is great at memorization and even those who memorized their multiplication tables in third grade can still sometimes draw a blank when put on the spot. Here are some quick ways to recalculate them instantly.

5 Times Tables: Cut the number in half and then times ten.

2 x 5 = 1 x 10 = 10
6 x 5 = 3 x 10 = 30
9 x 5 = 4.5 x 10 = 45

8 and 6 Times Tables: Even numbered times tables can be a bit easier to calculate in your head if you forget them. For the 8 Times table simply think of what the 4 Times Table is and double it. In the 6 Times Table, double the 3’s.

For Example: You can’t think of 8 x 8 so remember that 8 x 4 is 32 and double that to 64. remembering 8 x 12 could be tricky, but since 4 x 12 is 48 simply double it to 96. Likewise 6 x 7 might be hard to remember, but 3 x 7 is 21 and that doubled is 42.

Also for the 6 Times Table, any even number you are multiplying by 6 will be the in the ones place of your product. 4 x 6 = 24, 8 x 6 = 48, 6 x 6 = 36.

7 Times Tables: I hate to say it but for the 7’s you really need to memorize. One of the ways you can do this passively is to use a dry erase marker and write 2 – 3 of the multiplication facts on your bathroom mirror. Then every time you wash your hands, brush your teeth, or fix your hair, you will see them and automatically read them. Leave the same ones up for a week at a time and before you know it, you will have them memorized!

9 Times Tables: Hold your hands out in front of you and hold down the finger you are multiplying by 9. The fingers to the left of that one is the tens place and the fingers to the right are the ones place. This only works to the 9 x 10 multiplication fact, but for 9 x 11 you can add 90 + 9 to equal 99 and 9 x 12 = (9 x 10) + (9 x 2) = 90 + 18 = 108.

Another trick for the 9’s is to multiply by 10 and subtract the number.
For example: 9 x 7 = (10 x 7) – 7 = 63 The answer will be 1 less than the number you are multiplying in the 10’s place up through the 10’s tables.. 8 x 9 = 72, 5 x 9 = 45, 10 x 9 = 90.

10’s Times Tables: Just put a zero on the end! 10 x 256 = 2560.

11’s Times Tables: for single digits simply repeat the digit. 6 x 11 = 66, 9 x 11 = 99, etc. But for double digits, write the first digit, then add the two digits for the second number, and then write the second digit. Example: 15 x 11 = 1 (1 + 5) 5 or 165, 22 x 11 = 2 (2 + 2) 2 or 242

12 Times Tables: These are usually what we consider the hard ones, but if you break it down into the tens tables plus the twos tables, you will get them every time.

8 x 12 = (8 x 10) + (8 x 2) = 80 + 16 = 96
11 x 12 = (11 x 10) + (11 x 2) = 110 + 22 = 132
6 x 12 = (6 x 10) + (6 x 2) = 60 + 12 = 72

The lower times tables, the 2’s, 3’s and 4’s are easy to calculate in your head on the spot. Simply skip count for the 2’s and double that for the 4’s. The 3’s are easy enough to add when you need them.

While I still highly recommend memorizing your multiplication tables, when those facts escape you for the moment, the above tips can help you get back on track!

Free Graphing Calculator!

Have you ever priced a graphing calculator? Those things are outrageous. It occurred to me one day that they are almost as expensive as a cheap laptop. Why hasn’t someone figured out an app for that already? Turns out I was a little slow on the uptake, someone already had! Enter Desmos. It is a free app that you can use on your smart phone that IS a graphing calculator! It is also available with other functionality on the demos website. You can open an account and save projects and even create a teacher account and create activities for your students. To try it out go to For the record I am in no way affiliated with Desmos and do not receive any compensation for promoting it.

Why spend the big bucks when you can get a graphing calculator for free?! Have fun graphing!

Why is high school math so hard?

For a few, math just falls together and makes sense. But for most, one of the hard things about moving from elementary mathematics into the algebras is the abstract concept of having freedom to manipulate the problem in more than one method.

There are clear directions given, but we can choose how to think about the problem and develop our own path for solving it. It becomes more about understanding the relationship between the numbers than it is about solving a given operation. Using multiple operations within a single problem, mixing in language and then asking the student to determine how to solve it creates a different level of stress in each of us.

That much responsibility coupled with lack of specific direction is the perfect storm for math anxiety which make it all seem so much harder than it really is. The goal at EduGrafx is to illustrate through video and other multimedia the relationship between the numbers and how all the math rules work together. This provides a clearer understanding of the abstract concepts we ask our students to tackle. See how EduGrafx can help your student. Try watching some of my free videos on youtube.

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