Algebra Balance Scales from the National Library of Virtual Manipulatives
http://nlvm.usu.edu/en/nav/frames_asid_324_g_3_t_2.html
This uses a seesaw to represent an equation. The student is given an equation and begins solving it by placing the appropriate terms on right and left sides of the seesaw. For instance, for the equation -3x + 2 = -8 the student would place three “-x” balloons and two positive “1″ blocks on the left side of the fulcrum (i.e. equal sign). They would then place eight “-1″ balloons on the right side of the fulcrum. Once they do this and the seesaw is balanced, they are prompted to select addition, subtraction, multiplication, or division to solve the equation. They then type in how much they would like to add, subtract, multiply, or divide from both sides. The game then removes the appropriate balloons and tiles and shows the beam to be either balanced or unbalanced. If it is unbalanced, the student knows that they did not do the same things to both sides of the equation and therefore the two sides are no longer equal. The students then continue to add, subtract, multiply, or divide until there is an “x” on one side and a certain number of “-1″ balloons or “1″ blocks on the other side.
This manipulative does not just reinforce the fact that when solving, the same thing must be done to both sides. It also reinforces the concept of a variable and like terms. I would probably not be able to use this program until the end of the year, since quite a few of the equations have a variable on both sides of the equation (something I do not teach until the end of the year). To implement this game, I would have each of my students use a laptop to practice solving equations using the program first. After several rounds, I would then have them transition to solving these equations with a pencil and paper. I would have each student write a problem for the person next to them. Students would then trade problems and solve them. This game would provide a great introduction and reinforcement for the concept of solving equations.
Awesome graphic!!!