194/25 = 7.76 Each student gets 7 balloons, 7 x 25 = 175 balloons will be used 194 - 175 = 19 balloons remaining (Answer to part 1 of this question)
If each student needs 8 balloons 8 * 25 = 200 200 - 194 = 6 ballons needed (Answer to part 2 of this question)
We also could have found the answer to part 2 by saying that we had 19 balloons left over when the students each were given 7 balloons Each student needs another 1 balloon = 25 balloons, We have 19 left over 25 - 19 = 6 balloons need to be purchased (we got the same answer both ways so it is very likely we have the correct answer)