Why does the finger trick for multiplying by 9 work?

Why does the finger trick for multiplying by 9 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.

Do you know the 9’s trick with your fingers?

Take a look at your hands, with the proper finger still folded. Count the number of fingers that are to the right of the folded finger. For example, if you are solving 9 x 6, you will see that you have four fingers to the right of the folded finger. This means that the ones digit in your answer will be 4.

What are the nine multiplication facts?

9 times table

• 9 x 1 = 9.
• 9 x 2 = 18.
• 9 x 3 = 27.
• 9 x 4 = 36.
• 9 x 5 = 45.
• 9 x 6 = 54.
• 9 x 7 = 63.
• 9 x 8 = 72.

How do you do the 9 times table trick?

9 Times Tables – How Fingers Trick Works. STEP1:Hold both your hands up with palms facing you. Number the fingers from left to right as one to ten. STEP2:Now hold down the finger of the number you want to multiply by 9. Here in this example, we are going to multiply by 3, so the 3 rd finger is held down.

Can a finger be used to multiply 9?

The finger trick also cannot be used to multiply 9 by fractions or any other number that is not an integer. If you need to multiply 9 by any larger number, you can calculate the problem using a pencil and paper or use a calculator to solve the problem for you.

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.

How do you do multiplication with your hands?

Make sure that your fingers are pointing up, that your hands are next to one another, and that your palms are facing away from your body. Your hands are the basis for calculating the 9s times table. Assign your fingers a number by counting upwards from left to right.