How many different math problems can you make with the answer being 10?

Answer 1

An infinite number.

Here is a flavour:

11 - 1 = 10

12 - 2 = 10

13 - 3 = 10

1000 - 990 = 10

1000000 - 999990 = 10

then,

11.1 - 1.1 = 10

12.1 = 2.1 = 10

and that is just subtractions.

10/1 = 10

11/1.1 = 10

12/1.2 = 10

etc

1+9 = 10

1.1+8.9 = 10