Why does the 9 finger trick work?

Why does the 9 finger trick work?

As stated above, it’s because 9 is one less than our “rollover” number, 10. This actually works in any modulo system where the number you’re multiplying is one less than the “rollover” number.

How do you teach multiplying by 9s with finger trick?

Step 1: Hold up all 10 of your fingers. Imagine they’re numbered 1 through 10, as you see in the picture. Step 2: Since you’re multiplying 9 x 7, you fold down the seventh finger, like this. Step 3: Count the number of fingers to the left of the folded finger (6).

What is the trick of 9 Table?

Count all the fingers after the one that’s held down – 6. This is the last number of your answer. To find the answer to another 9 × table question, just hold down the correct finger and count the fingers on either side. So you hold down your 5th finger for 5 × 9, your 7th finger for 7 × 9, and so on.

How does the nines trick work?

Here’s how it works: Hold up both hands in front of you with your palms facing away, and pick an equation to solve that involves multiplying by nine. For example, 9 x 4. Try this trick with any single digit number that you want to multiply by nine.

What is the trick to multiplication?

Tricks by Number

1. add the number to itself (in other words, double it) Example 2×9 = 9+9 = 18.
2. double, then double again.
3. Cut in half, then times 10.
4. when you multiply 6 by an even number, they both end in the same digit.
5. 7×8.
6. Double, double, double!
7. is 10× the number minus the number.
8. put a zero after it.

How do I teach my 10 year old times tables?

Here are our eight highly effective tips on how to teach times tables the easy way.

1. Hang up a times table sheet.
2. Make sure they can walk before they can run.
3. Teach your kids some tricks.
4. Listen to some fun songs.
5. Stage a multiplication war.
6. Draw a Waldorf multiplication flower.
7. Quiz them regularly, but not incessantly.

Can you use your fingers to do the 9s times table?

Using the fingers trick for your 9s times tables is a great way to become more familiar with multiplication. However, eventually you might want to simply memorize these calculations to save yourself time and effort. Thanks! Remember that this trick only works for the 9s times tables between 9 x 1 and 9 x 10.

Where do you fold your finger when multiplying 9 x 2?

When you multiply 9 x 2, you will fold down the finger that is second from the left: your left ring finger. When you multiply 9 x 6, you will fold down your finger in the “6” spot: your right thumb. Remember that you can solve any multiplication problem from 9 x 1 to 9 x 10 in this manner.

Do you always start with 9 in the Nines times table?

The nines times table has the great trick that the digits of your answer always add up to 9. This works as follows: Remember that the tens digit of 9 x some number will be some number minus one. For example, the tens digit of 9 x 3 will be 3-1, or 2. Therefore the answer to 9 x 3 should begin with 2.

How many fingers are to the left of the folded finger?

Count the number of fingers that are to the left of the folded finger. Ask yourself how many fingers are standing up to the left of the folded finger. For example, if you are solving the problem of 9 x 6, there should be five fingers (all the fingers on your left hand) standing up to the left of the folded sixth finger (your right thumb).