Ratio 100:50
100 : 50 <– always ÷ the second number until u can’t. So here. 50÷50 =1 and 100÷50 =2 so the answer is 2:1
Percentage
Part ur figuring out÷ all of it (total) × 100
Calculating cell sizes?
1mm = 100um then ÷ by the amount of cells across or up and down the way
Length?
Across the way Horizontal
Breadth?
Up and down vertical