Dicey Operations Ayah Ahmed

I first got the numbers 8,7,1,0 and first tried 81+70 but that equals 151, which was too far from the target of 100. I then tried changing the last digit and so did 81+07 which equalled 88, but was too far again, so then I tried changing the 1 for the 7, getting 87+10 which equalled 97, and with a single digit difference. I thought that was the one.