The document subtracts 6s from 48, 7s from 42, and 9s from 63 to determine how many of each digit exists in the factorials. It finds that there are 8 sixes in 48!, 6 sevens in 42!, and 7 nines in 63! by repeatedly subtracting the digits and tracking the results.

1. 8 6 48 6 42 48-6 36 42-6 6 30 36-6 6 24 30-6 6 18 24-6 6 6 12 18-6 6 6-6 0 12-6 6 How many 6’s have been subtracted? That means, there are 8 sixes in 48! 48 ÷ 6 =

2. 6 7 42 7 35 42-7 28 35-7 7 21 28-7 7 14 21-7 7 7 14-7 7 0 7-7 How many 7’s have been subtracted? That means, there are 6 sevens in 42! 42 ÷ 7 =

3. 7 9 63 9 54 63-9 45 54-9 9 36 45-9 9 27 36-9 9 18 27-9 9 9 9 18-9 9-9 0 How many 9’s have been subtracted? That means, there are 7 nines in 63! 63 ÷ 9 =