What is the largest remainder possible if the divisor is 10?

I am helping my child and do not know how to do this

Please show me how to and how to explain it.. Thank u

2 answers

Will it be 1,2,5? So 5 being the largest?
No. The largest remainder is 9.

99/10 = 9 with a remainder of 9
100/10 = 10 with no remainder