This is a great 151 page set of weight activities for any math center or classroom! This set uses non-standard weight measurement using a balance. For example, lightest & heaviest, what is lighter/heavier, about the same weight as, and how many cubes/bears something weighs.
Not sure how heavy to go for your workout? DailyBurn trainer Ben Booker recommends a dumbbell test to figure out the right weight for you. If you can't maintain form before reach 14 reps, pick a set of weights five lbs. lighter.