Logic puzzles help students develop solid critical thinking and problem solving skills in the early grades and is a great way to engage students. In addition, they are fun and provide lots of opportunities for students to share what they are thinking and how they determined the answer. The logic puzzle I want to share with you today is called Weight Logic.
To complete the weight logic puzzles, students use the sum of the symbols shown on the scale to determine the value of each symbol. For many students, this task seems simple. You guess and check the values until you find a combination that works. But that level of thinking is just the beginning. The real critical thinking comes in when students use strategies, other than guess and check, to determine the value of each fruit.
For example, on puzzle #5 (to the top right), if students recognize that the watermelon and two strawberries on the left side are included in the two pieces of watermelon and two strawberries on the right side, they can subtract the 10 on the left from the 12 on the right to see that the leftover watermelon slice has a value of 2. Once they know that, they can determine the value of the strawberry. How's that for fostering algebraic thinking in elementary school!
For puzzle #6 (to the bottom right), students recognize that there are three watermelon slices on the right whose total value must be a multiple of three. The only multiple of three that is less than five is 3. If students subtract 3 from 5, then you discover the value of the bunch of grapes is 2 and the value of the lemon slices is 1. Students can then double-check their values using the left side to see if their solution works.
How awesome would our students be if they could articulate that level of thinking? It will take time for students to arrive at these solutions, but once they've mastered guess and check, encourage them to look for other ways to solve the problem. Be sure to have students share their solution strategies with other classmates as well.