-8
639 - 452 = 187
there are 899 whole numbers that have three digits.
Assuming you mean permutations of three digits, then the set of numbers that can be made with these digits is: 345 354 435 453 534 543 There are six possible permutations of three numbers.
There are 900 three-digit numbers.
Your answer is, depending on the order of your subtraction, either positive or negative 198
Three digits.
depends on your answer
100
Yes.
757
Yes it matters. Subtraction is not commutative. Example: 5-2 = 3 (positive three), but 2-5 = -3 (negative three)
None, because you do not have three even digits. None, because you do not have three even digits. None, because you do not have three even digits. None, because you do not have three even digits.