6 x 89 is 534
6 x (90 - 1) is 534. BUT you have to subtract 90 from 1 and that's 89. So then you multiply 6 by 89.
6 x 90 is 540 and 6 x 1 is 6. you take 540 subtract 6 and that's 534.
540 - 6 is 534.
57C7, the answer is 264,385,836 different selections
M is smaller than km
1000m=1km
so divide by 1000
basically move decimal 3 places to left
put zero in front
0.0548km