The activity surrounds giving different groups a set of 10 cans (planets plus our Moon) and two triple-beam balances (initially with me saying, "Use two balances;
(The activity; surrounds; giving different groups a set of 10 cans (planets plus our Moon) and two triple-beam balances (initially with me)
The activity
surrounds
giving different groups a set of 10 cans (planets plus our Moon) and two triple-beam balances (initially with me