This PHET simulation says it only teaches ratios ("6.RP.A.3",),
but I think it also teaches algebra!
The balance beam is not balanced when the equality relation does not hold: there is then an inequality relation between the masses given the position of the fulcrum.
Adding the same amount of mass to each side does not change whether the balance remains balanced (and subtraction is the inverse of addition, and integer multiplication is repeated addition).
Given a different amount of mass on each side of the balance, what is the mathematical analogue of balancing the equation by moving the fulcrum just?
The balance beam is not balanced when the equality relation does not hold: there is then an inequality relation between the masses given the position of the fulcrum.
Adding the same amount of mass to each side does not change whether the balance remains balanced (and subtraction is the inverse of addition, and integer multiplication is repeated addition).
Given a different amount of mass on each side of the balance, what is the mathematical analogue of balancing the equation by moving the fulcrum just?