There is a method to the madness of mathematics no matter how scary they can look. Numbers are practically the only thing in this universe that make sense, but the trick is to figure out all the tricks. Here are a few math hacks to help impress your friends and your 11th-grade algebra teachers.
#1. 9 Times Tables
Begin by writing your “9” times table equations. Next, write 10 numbers in sequence from zero through nine from the top as the first part of the answer. Third, write 10 numbers in sequence from zero through nine from the bottom as the second part of your answer.
#2. Multiplying By 6, 7, 8, 9, and 10
Assign numbers to your fingers from your thumb to pinky, so thumbs represent 6, and your pinkies represent 10. For example, 9 x 8, the first digit of the result will be the number of fingers from 9 through 8, which is 7 (within the red circle).
The second digit of the result is found by multiplying the number of fingers outside of 9 on your left hand (1) by the number of fingers remaining on your right hand (2).
9 x 8 = 72.
#3. Memorizing The First 39 Digits Of Pi
If you can memorize these three sentences and the number of letters in each word, you can remember the first 39 digits of Pi.
Pi = 3.141592653589793238462643383279502884197
#4. Multiplying Large Numbers In Your Head
First, subtract the two numbers (97 & 96) from 100 (3 & 4) and add them together (7). Next, subtract that number from 100 to get the first part of the result (93). Finally, multiply the 3 & 4 to get the second part of the number (12).
97 x 96 = 9312.
#5. Finding The Percentage Of A Number
Use these simple steps for finding the percentage of a number.
#6. Converting Celcius To Fahrenheit And Vice Versa
To get the approximate conversion from Celsius to Fahrenheit (and the other way around) follow these easy steps.
#7. Multiplying By 11
Split 78 up into 7_8. The middle digit is found by adding the 7+8 to make 15. Since it is a two-digit number, the one is carried onto the 7, making the first digit now 8.