Thus

Number of teeth in
smallest wheel.
Number of cutters in
the set.
12 × 8 = 96

Then

Number of cutters
in the set.
Number of
cutters.
8 - 6 = 2

And

Number of teeth in
smallest wheel.
The number of the
cutter
The number of teeth
in the largest wheel.
12 × 8 ÷ 300

Here

12
8
300 ) 960 ( 0.32
900
600
600

Add the 2 to the .32 and we have 2.32 to divide into the 96.

Thus