This activity helps teach ...
13.NF.1 add and subtract fractions with unlike denominators (including mixed numbers) by replacing given fractions with equivalent fractions in such a way as to produce an equivalent sum or difference of fractions with like denominators (e.g., 2/3 + 5/4 = 8/12 + 15/12 = 23/12)
This activity calls for the children to solve four addition or subtraction fraction word problems using pattern blocks to model. All fractions have the denominator 2,3,or 6 so the children can use the shapes to make equivalent fractions before they solve the problem.
For each problem the children will estimate the answer, and explain why it is reasonable. They will then use the pattern blocks to create a new expression with equivalent fractions, and finally solve the problem using an algorithm.
I would recommend that this activity be done in as a small group lesson, so that you can model using the pattern blocks and clearly show your expectations for the algorithm.