To remember your age . take your house number and double it then add 5 and multiply by 50 the add your age and the number of days in a year and subtract 615 from it
the first two numbers are your house numbers the rest are your age
can you explain why?

This is because as you add and subtract the numbers, you are really just moving them around nonsensically, to leave you back at the original two numbers. the same thing works with phone numbers. I do this sometimes as a magic trick.

Step-by-step explanation:

14x2

28+5

33x50

1650+15+365

2030-615

=1415

This works because most of the numbers are already set, so there are only two number that change, the math problems work to ensure that you reach the point where only the two variables are displayed. this also works with phone numbers.