All Children Should Know This.
Remember this?
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | |
|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |
| 2 | 2 | 4 | 6 | 8 | 10 | 12 | 14 | 16 | 18 | 20 |
| 3 | 3 | 6 | 9 | 12 | 15 | 18 | 21 | 24 | 27 | 30 |
| 4 | 4 | 8 | 12 | 16 | 20 | 24 | 28 | 32 | 36 | 40 |
| 5 | 5 | 10 | 15 | 20 | 25 | 30 | 35 | 40 | 45 | 50 |
| 6 | 6 | 12 | 18 | 24 | 30 | 36 | 42 | 48 | 54 | 60 |
| 7 | 7 | 14 | 21 | 28 | 35 | 42 | 49 | 56 | 63 | 70 |
| 8 | 8 | 16 | 24 | 32 | 40 | 48 | 56 | 64 | 72 | 80 |
| 9 | 9 | 18 | 27 | 36 | 45 | 54 | 63 | 72 | 81 | 90 |
| 10 | 10 | 20 | 30 | 40 | 50 | 60 | 70 | 80 | 90 | 100 |
I do not remember exactly what age I was when I learned the times tables. Even for my children I do not remember exactly when they learned them. But they did learn them. And I think most of my children's schoolmates also learned them. When I say they "learned" them - I mean they memorized them. Ask me or my kids what is 9 x 7 and we know it is 63 right away.
Kids Today
Ask the kids I see in Ecuador today who are maybe 10 years or older what is 9 x 7 and I can tell what you will very often see: The child will start counting with his or her fingers "9" with one finger, "18" with two fingers, "27" with three fingers...up to 7 fingers. If they do it right they get "63". About half the time they get it wrong.
So what is so terrible about this? We have calculators now and we don't have to do this anymore - right?
WRONG!!!
First Problem - learning long multiplication
Look at this math textbook explaining how to do long multiplication. This is just a two digit problem. A three digit problem is much worse. If this is in the textbook it will probably be on the test! Try doing this problem without using anything from the times tables. Just the first step (9 x 5) takes a full minute (9, 18, 27, 36, 45). A students chances of doing this problem correctly during a test under time pressure is about zero.
Being unable to do something correctly and doing poorly on tests will affect the students confidence - and they will conclude "They don't like math". Compare this to a student who does know the times tables. They still have to be careful and do the steps correctly - but when they do they get exactly the right answer. There is a satisfaction that comes with seeing your answer exactly correct that becomes contagious. Real earned success builds confidence.
Second Problem - learning fractions
For a student knows the times tables well the explanation below of adding fractions will make sense. The student will understand the pattern that 1/3 is the same as 5/15 as both the numerator and denominator is multiplied by 5. But this pattern will basically be a big mystery if you don't know your times tables well. This problem occurs over and over with all textbook explanations of fractions. Adding fractions, multiplying fractions, finding the least common denominator, etc. If your child does not really know the times tables he or she is destined to being in a complete fog when trying to really understand lessons about operations with fractions.
I learned this firsthand recently when I was asked to help tutor a young man in mathematics. I had tutored math several times before for students learning geometry, algebra and calculus. So the students I tutored knew their times tables. But this young man didn't. And trying to teach him these two things (long multiplication and fraction problems) was not possible. I instructed the Mom she should take away all his social media devices until he learned the times tables. I never saw either of them again.
Third Example - Understanding science.
Look at this famous video of Carl Sagan explaining how Eratosthenes determined pretty accurately the circumference of the earth in about 200 BC. Being able to sit and listen to this and completely understand it requires you know that 7 degrees is about 1/50 of the a complete 360 degree circle (approximately). And 800 km times 50 is 40,000 km. You understand lots of things in this world quicker and more completely when you just know your times tables.
Just Learn the Times Tables
Just about any child can memorize the times tables. You can use flash cards. You can give them an ice cream if they learn one row of the table. Ask them questions at dinner time. I always taught my kids there is only one question that is a stupid question. Here it is:
"Why Do I Have To Learn This"?
Kids are literally learning machines. They learn incredibly quickly. They can learn just about anything. So even if you still really agree with everything I have said here - just have your kids learn the times tables. Do it this week.