1、When Ma Xiaohu was doing a subtraction problem, he mistakenly wrote the unit digit of the minuend as 5 instead of 3, and the tens digit as 0 instead of 6. He also wrote the hundreds digit of the subtrahend as 2 instead of 7. The resulting difference was 1994. What should the correct difference be? $\qquad$
【Analysis】Digital problem.
If the unit digit 3 of the minuend is written as 5, then the minuend increases by 2, and the difference increases by 2, so it should be subtracted; if the tens digit 6 of the minuend is written as 0, then the minuend decreases by 60, and the difference decreases by 60, so it should be added; if the hundreds digit 7 of the subtrahend is written as 2, then the subtrahend decreases by 500, and the difference increases by 500, so it should be subtracted; therefore, the correct difference should be 1994-500+60-2=1552.