We are given a mixed number which is 2 and 1/2. We convert it to a whole number by converting first the fraction part of it into decimal form. One half in decimal form is 0.5. Therefore, 2 and 1/2 in decimal form would be 2.5. Rounding it off, for it to be a whole number would be 3.
2 and 1/2 rounded off to a whole number is 3.