November 5th 2021
Check out these amazing maths magic tricks this week!
Multiplying by 6
If you multiply 6 by an even number, the answer will end with the same digit. The number in the ten's place will be half of the number in the one's place.
Example: 6 x 4 = 24.
The Answer Is 2
- Think of a number.
- Multiply it by 3.
- Add 6.
- Divide this number by 3.
- Subtract the number from Step 1 from the answer in Step 4.
The answer is 2.
Same Three-Digit Number
- Think of any three-digit number in which each of the digits is the same. Examples include 333, 666, 777, and 999.
- Add up the digits.
- Divide the three-digit number by the answer in Step 2.
The answer is 37.
Six Digits Become Three
- Take any three-digit number and write it twice to make a six-digit number. Examples include 371371 or 552552.
- Divide the number by 7.
- Divide it by 11.
- Divide it by 13.
The order in which you do the division is unimportant!
The answer is the three-digit number.
Examples: 371371 gives you 371 or 552552 gives you 552.
- A related trick is to take any three-digit number.
- Multiply it by 7, 11, and 13.
The result will be a six-digit number that repeats the three-digit number.
Example: 456 becomes 456456.
The 11 Rule
This is a quick way to multiply two-digit numbers by 11 in your head.
- Separate the two digits in your mind.
- Add the two digits together.
- Place the number from Step 2 between the two digits. If the number from Step 2 is greater than 9, put the one's digit in the space and carry the ten's digit.
Examples: 72 x 11 = 792.
57 x 11 = 5 _ 7, but 5 + 7 = 12, so put 2 in the space and add the 1 to the 5 to get 627