Ihave 4 digits. my 7 is worth 7 ∗ 1,000. my 2 is worth 200. one of my 4s is worth 40. the other is worth 1/10 as much.

7 • 1000=7000. Your 1,000 place is 7. Your hundreds place is 200. So far your number is:
7,200
4 would go in the tens place because in 40, there is a four in the tens place. Finally 1/10 of 40 is four because 40/10=4.

Your number is 7,244