you add up all the numbers to get the total then divied the single number (eg. 8) by the total. It will then show up as a decimal so in order to get rid of the decimal you multiply by 100. ( eg. 8 ÷50=0.16 → 0.16×100= 16 → 16% )
to use integers for certain problems and equation on math, i can also use it for future use in life in case i need it, Its very helpful to learn since it isnt that complicated nor hard, its just a good skill to keep in mind as a student.