I'll Guess Your Age

Choose a number from 1 to 9 which is your favourite number

Multiply your number with 2

ADD 5 YOUR RESULT

Multiply the result by 50

If you already celebrated your birthday this year add 1768 to your result

OR

Your birthday is coming add 1767

the first number you chose are nothing and 2 digot

You will have 4 digit number if not then something gone terribly wrong

You need to substract the year from your birthyear

the first number you chose are nothing and after 2 digits are your age

8 x 2=16, + 5 =21, x 50=1050, add 1768 =2818, subtract from year of birth, using just last two numbers of that result as my age produces a number that is off by 51 years.  We are being trolled even if OP is sincere. The premise is junk.

Let's solve this with maths!

Step 1:    x

Step 2:    2x

Step 3:    2x+5

Step 4:   50(2x+5)=100x+250

Step 5:    Assume we have already had our birthday (2019 considered)

               100x+2018

Step 6:    Subtract birthyear. So, the birthyear is equal to 2019 (we have already had our birthday) subtract our age. 2019-y. (y is age)

So, 100x+2018-(2019-y)

= 100x-1+y.

Therefore this works if you are under the age of 100; you get your first digit as you original number x, followed by y, your age. eg you get the number QRS. Q is your number, and RS is your age; if your age is one digit, R will be a zero.

Unfortunately, this "trick" is one year out of date (hence the -1 in the equation).

I got 14 which is one year younger. And he didn't make this up, this can be found on wikihow. 

you don't talk like 39

Check my previous comment.

It 2018 version sorry

are you on time machine like things?