Not Just One Direction

Objective:
Child will understand the directionality of addition and subtraction.

Essential Question(s):
How can we use grouping to better understand addition and subtraction?

Special Materials:
A deck of cards without the kings, queens, and jacks; pencil and paper

Bricks Required:
9 each of two different colors of 1×2 bricks, 9 clear 1×2 bricks and a 16×16 plate to stick them on

Project Structure

Engage:

1. Ask child to explain how addition and subtraction are related.
   1. Answers may include that they are opposites.
2. Explain that addition can be used to help with subtraction and subtraction to help with addition.

Explore:

1. Hand out cards (at least one each of 1-9), a 16×16 plate, and bricks
2. Ask child to draw two cards and create an addition sentence with one number missing (card x + ___ = card y, where y is the larger number) out of bricks on the plate. Child should line up the bricks so it’s easy to see where the blanks are.
   1. Child can use the clear bricks to help count how many are missing to fill in their equations and record them on paper.
   2. Child should repeat this process a few times.
3. Child then continues to draw cards, this time creating a subtraction sentence that focuses on the unknown addend, and recording their work.