Remember how to take away numbers from the next digit?
Well, 0-6 is 4, so take away 1 from the 10s (80-10=70)
Then 70-90=80, so next place is also affected. (200-100=100)
Then, 100-700=400. So, thousands place is taken away.
The total difference for this question is 484.
Have a nice day! ♪