This is a pretty cool birthday math trick! This math trick will involve some math calculations, so be sure the person does the math correctly (may need to use a calculator).
Note: Make sure you try this trick out for yourself first, using your own birthdate.
STEPS TO THE MATH TRICK
Add 18 to the month they were born
Multiply by 25
Subtract 333
Multiply by 8
Subtract 554
Divide by 2
Add their birth date
Multiply by 5
Add 692
Multiply by 20
Add only the last two digits of their birth year
Subtract 32940 to get their birthday!
Pretty Cool Math Stuff!
Here’s an example below…
Let’s suppose someone has a birthdate of August 22, 1964.
So we want to use the format of month/day/year so this birthdate would be08/22/64.
Notice we only used two digits for the year.
18 + 8 = 26
26 x 25 = 650
650 – 333 = 317
317 x 8 = 2536
2536 – 554 = 1982
1982 / 2 = 991
991 + 22 = 1013
1013 x 5 = 5065
5065 + 692 = 5757
5757 x 20 = 115140
115140 + 64 = 115204
1295204 – 32940 = 82264
The reason this trick is so fun is that math is just a big, secret puzzle.
If your students love “solving a puzzle,” that’s the entire idea behind my Math Mysteries. They take all the “boring” math standards (like multi-step calculations!) and wrap them in a fun, high-engagement “case file.”
It’s the ultimate “math trick” to get students excited for your math block!
CLICK HERE TO SEE THE MATH MYSTERIES!
