It is the percentage efficiency.
Work output divided by Work input Times 100
100
100 divided by 4 times 5 is equal to 125.
100 times 101 divided by 2 is equal to 5,050.
2000
0.56
550 divided by 5750
100 100 times 100 = 10000
100 .... wow that is cool!
100 divided by 25 plus 8 times 4 is equal to 36.
100 divided by 25 times 64 = 256
The way I did it in school a long time ago? 450 divided by 100, times 15 (67.5)