Lesson 9 Add and Subtract Within 100
Let’s find the difference in our own way.
Warm-up Which One Doesn’t Belong: Tens and Ones
Which one doesn’t belong?
Activity 1 Sort and Find the Value
Match each expression to a base-ten diagram.
Choose 1 addition expression and find the value of the sum.
Choose 1 subtraction expression and find value of the difference.
Activity 2 Add or Subtract
Find the value of each expression. Show your thinking. Use blocks if it helps.
Find the value of each expression. Show your thinking.