If you like partner/group work then this activity is perfect. Students work in pairs. One partner solves column A, the other solves column B. The fractions in each row should reduce to the same answer. That way students can know they are doing the activity correctly by comparing their answer with their partner's. I really like encouraging students to self-check their work and this type of activity works really well for that. It also encourages them to look at one another's work if their answers aren't matching.
One variation you could do is have your students split into two teams; a red team and a blue team. The red team solves column A and the blue team solves column B. For every problem, students need to get up and find someone from the other team who solved a problem in the other column. For example a student from the red team solves problem 2 in column A and compares their answer with a student from the blue team who solved problem 2 in column B. Together they compare their answers to make sure they both reduce to the same fraction. After this they find a different member from the other team to verify the next problem. This way students are constantly being paired with different people and you don't have two strong students or two weak students being paired together for the entire worksheet.