lori finished 4 times as many math problems at home as she finished in class. she finish 25 math problems at home. how many math problems did lori finish in class

What you have to do is look at the problem and read carefully. You see that Lori finished 25 math problem at home, and she finished more in school. So, that leads that we can t divide or subtract because that would give us a smaller number then 25. We have either addition or multiplication. It would be multiplication because you says 4 TIMES, which is a key word to multiplication. You take the amount of problems at home and MULTIPLY them by 4. Doing 25 times 4 which gives you 100.