Motley Crab Adder found three and then found seven more. How many did he find all together? Use a math balance to find out, Put a weight on the three peg and a weight on the seven peg on one side of the beam and balance the beam with one weight.
Subtraction (finding the difference):
Ork is nine. Zlu is six. Ork is how much older than Zlu? Use a math balance to find out, Put a weight on the nine peg on one side of the beam and a weight on the six peg on the other side of the beam and balance the beam with one weight.
Sir Crab Multiplier found eight two times. How many did he find altogether? Use a math balance to find out, Put two weights on the eight peg on one side of the beam and balance the beam with a 10 and one other weight.
A truck can carry four. How many truck loads to carry 20? Use a math balance to find out, Put 20 on one side of the beam and balance the beam with fours only.
If possible, precede any work with a math balance with a play period on a teeter totter where small children are asked to balance large children and one child is asked to balance several children. In responding, they will discover the principle crucial to the working of a math balance, that weight times distance equals weight times distance. They will also experience what equality “feels” like.
To appreciate the importance of having elementary school students work with a math balance, ask some first or second graders what they think of the following equations: 5 = 2+3, 7 = 7, and 1+9 = 4+6. They will probably reject them, insisting that 5 = 2+3 should be rewritten as 2+3 = 5, that 7 = 7 should be rewrittten as 7+0 = 7, and that 1+9 = 4+6 should be rewritten as 1+9 = 10 and 4+6 = 10. In other words, they will probably not view the equal sign as meaning “equals” or “the same as.” Instead, they will view it as a sort of punctuation for the location of “the answer.” Having them work with a math balance can help remedy this.
Math Games & Activities, Vol. 1