Dicey Operations Ayah

The numbers I was given were 7, 4, 2, and 1. To start off, I tried to find a number close to 30, since 70+30 = 100, which is the direct target. After I looked, I realized 24 (I did do 21, but 24 is still accomplishable as a part fo the solution) was the closest to 30, then I did 21+70+the remaining 4 (so 21+74), and I got 95, and since it has a single digit difference, it was the closest answer