Lesson 2 Relate Addition and Subtraction

    • Let’s look at the relationship between addition and subtraction.

Warm-up Number Talk: Connect Addition and Subtraction

Find the value of each expression mentally.

Activity 1 Cube Tower Addition and Subtraction

Write an addition and a subtraction equation to match the connecting cubes.

  1. Connecting cube tower, 4 blue, 2 yellow. 
  2. Connecting cube tower, 3 blue, 5 yellow. 
  3. Connecting cube tower, 4 blue, 5 yellow. 
  4. Connecting cube tower, 4 blue, 3 yellow. 
  5. Connecting cube tower, 6 blue, 3 yellow. 

Activity 2 Find the Unknown Number

Find the number that makes each equation true.
Explain to your partner how you found it.

Activity 3 Differences I’ve Got

two students sitting at desks with different equations in speech bubbles

  1. Color the differences you know the value of from memory.

    Subtraction facts chart.

  2. Write each difference that is not colored, on an index card.

    Write an addition equation on the card that can help you find the value of the difference.