Counting by tens is faster than counting by ones because you skip more numbers in between 10 and the next number than just counting by ones
Ha 145271 answer dunno hehe
I believe the most logical answer would be is to divide so us the kcf method keep change flip so 5 stays the same then change division into multiplication then flip the fraction 1/3 into 3/1 so now we have 5 times 3 is 15