if i have someone write any 5 digit number down, i'm supposed to be able to know the answer to it and 4 others

Question

the other person writes a 5 digit number down, and im supposed to know the answer to it plus 4 other 5 digit numbers. they then fill in the second, i fill in the third, they fill in the fourth and i fill in the fifth and final 5 digit number. i am suposed to have the right answer. Please help!

Answer 1

1. Someone writes down 83,521
2. You write down 16,479
3. They write down 37,727
4. You write down 62,273
.......
11. They finally write down 28,466
The sum is 528,466. Why? Every time they write down a number, you write down a number that makes the total 100,000. Notice that #1 and #2 add up to 100,000, and so do #'s 3 and 4. Continue this and let them end with #11 so they don't catch on.

Answer 2

84372, Good enough 5 digit number for you?

Answer 3

If you want her phone number that badly, just ask.