Okay so 29 students is 100% of the class, if only 25% wore sweatshirts that means the remaining did not so 100%-25%=75%. We want to convert that percentage to a decimal to multiply so 75% is the same as 0.75, multiply that by 29 and we get 21.75, depending on how the teacher or question wants it we will say about 22 students did not wear them as we rounded up
