Algebra Use groups of 2. Materials: Counters, balance, cards

Weight a Minute

Select a small classroom object--for example, a pencil. Place the object on one pan of the balance. Then place counters one at a time on the other pan until the pans balance. This tells you the weight of the object in counters. Next, place more counters on the pan with the object. Add the same number of counters to the other pan.

On a card, write an equation describing what you have done. Use a variable to represent the object. (For example, if your object weighed 32 counters and you added 2 more counters, you would write x + 2 = 34.)

Repeat the above for two other objects, using a different variable for each. Trade cards and objects with another pair. Use counters and the balance to guess the object represented by each variable.