Group Activity Cards
Use groups of 2.
Materials: Counters, balance, index cards
| Weighty Matters
Find the weight in counters of three small classroom objects--for example, a piece of chalk. Weigh one object at a time. Place the object on one pan. Then place counters one at a time on the other pan until the pans balance. Next, add counters to or take them from the first pan. Add to or take from the other pan the same number of counters.
On a card, write an equation that describes what you have done. Use a different variable to describe each object. For example, if your object weighed 45 counters and you added 3 more counters, you could write x + 3 = 48.
Trade cards with another pair and use counters and the balance to guess the object represented by each variable.