34/70 as a percentage is 48.57%. This number tells you how much of a whole 34 parts out of 70 represent when you look at it in terms of 100.
The fraction 34/70 can be reduced to 17/35, but the decimal and percentage forms stay the same. Seeing it as a percent makes it easier to compare with other values that are already expressed out of 100.
In everyday situations, you might round 48.57% to 49% for quick estimates, but the more precise figure is useful when exactness matters, such as in reports or calculations.