A percentage is a fraction out of exactly one hundred; indeed, per-cent literally means 'out of one hundred'. When making a calculation of a mark, you obtain a decimal on the calculator which is less than 1, or 100%. Thus does a mark of 36 out of 50 become 72 out of a hundred, and thus 72%. When calculating the mean mark of a set of marks, add up all the numerators (top number of a fraction, and the mark you got) and the denominators (the bottom number and the total marks available) to obtain a total mark, then divide one by the other. If you have sat three tests, each out of fifty possible marks, and scored 30, 20 and 50, you have obtained a mark of 100 out of 150, which works out as 0.6666 recurring. Always round up to the nearest whole number when finding it to no decimal places so, after multiplying by 100%, you have scored 66.66 recurring percent, or 67% to the nearest whole percentage. When you speak of giving 110%, this is mathematically impossible but implies that for every 1 degree of effort (or 1.00) you will give 1.1 instead, giving above the odds. This phrase makes itself known in the sports and business spheres. There is a debate over whether it is 'percent' or 'per cent', with the former American spelling taking precedence. Formerly it used to be "per cent" which is today used in formal and legal documents such as when writing transcripts of Parliamentary proceedings.

Marks in Percentage = (Marks obtained * 100) / Total marks

100*600

Divide the points given for correct answers by the total number of possible points if all answers were correct. Multiply that ratio by 100% to find the percentage correct. Decide on the required percentage correct for each grade, and assign grades accordingly.

There are many ways to decide the percentage correct required for each grade. The best requires a deep understanding of the material and what level of mastery you insist on from your students. The worst is to use a formula such as ≥90% is "A", ≥80% is "B", ≥70% is "C", ≥60% is "D", and anything else is "F".

You could also try this approach. If any are missed, give an "F". If all are correct, give an "A". Allow any number of free retries until every student has the grade they want.

There are many ways to decide the percentage correct required for each grade. The best requires a deep understanding of the material and what level of mastery you insist on from your students. The worst is to use a formula such as ≥90% is "A", ≥80% is "B", ≥70% is "C", ≥60% is "D", and anything else is "F".

You could also try this approach. If any are missed, give an "F". If all are correct, give an "A". Allow any number of free retries until every student has the grade they want.