Answer:
10
Step-by-step explanation:
100 - 10 = 90 ( 1 )
90 - 10 = 80 ( 2 )
80 - 10 = 70 ( 3 )
70 - 10 = 60 ( 4 )
60 - 10 = 50 ( 5 )
50 - 10 = 40 ( 6 )
40 - 10 = 30 ( 7 )
30 - 10 = 20 ( 8 )
20 - 10 = 10 ( 9 )
10 - 10 = 0 ( 10 )
we subtract 10 from 100 10 times
