42/51 as a percentage is 82.35%. This value tells you that the fraction is a little more than four‑fifths of a whole.
The fraction 42/51 can be reduced by dividing both numbers by 3, giving the simpler form 14/17. Whether you keep it as 42/51 or write it as 14/17, the size of the part stays the same, and it still equals the same percentage.
In everyday situations, you might see this percentage when comparing scores, budgets, or any measurement where you need to know how much of a total you have. Knowing that 42 out of 51 items represent about 82.35% helps you quickly gauge how close you are to completing a goal.