Grade level: 3rd grade
Common Core Standards: 3.NF.3,3.G.1, 3.G.2, 3.MD.7d
Time for the lesson: 2 hours
1) Review working definition of fraction: A whole cut into equal parts.
2) Read Underachievers by Holly Young from pg. 15 to pg. 21.
3) Divide Geometric shapes into parts with equal area:
- Looking at pattern blocks (all students receive access to many different blocks per table group), ask them to decide which ones could make 1 whole? [all of them can]
- Ask them to decide which blocks can be cut in ½ using another shape? Model with the hexagon and trapezoid.
- Using the handout (page 1), ask students to work independently first and then share responses. Look for misconceptions. Encourage students to be creative with how they cut their shapes.
- Looking at pattern blocks, ask students: Which blocks can be cut into thirds using another shape? What do they have in common? Can you divide the other shapes? Why or why not?
- Using the handout (page 2), ask students to work independently first and then share responses. Look for misconceptions. Encourage students to be creative with how they cut their shapes.
- Looking at pattern blocks: What other fractions can any of the shapes be divided into using pattern block shapes? Discuss?
- How can we divide up any shape into a number of equal parts – discuss and look at strategies (cut and fold). Prove and justify! Using handout (page 3): Irregular shapes – how to do it? Use graph paper behind it, handout page 4 – how can that help?
- Using handout (page 5): Look at shapes that have parts shaded in – what is the fractional part that is shaded? Ask students to share strategies.
4) Exploration: Ask students to use a pattern block repeatedly to create a larger version of itself. For example – 9 squares can be placed to create a larger square. Then ask what fraction each original piece represents. In the square example, the fraction is 1/9.