40/90 as a percentage is 44.44%. This is the rounded figure you get when you look at the fraction as part of a whole.
The fraction 40/90 can be simplified to 4/9, which is a common ratio in many everyday situations. Even though the numbers look different, they represent the same portion of a whole.
Knowing that 40/90 equals about 44.44% helps when you need to compare parts of a total, such as when budgeting, measuring ingredients, or analyzing data. It gives a quick, easy‑to‑understand picture of just under half of something.