Number Trick

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SWBAT write expressions given successive steps.

Big Idea

Can students write expressions to represent steps in problem-solving?


5 minutes
  • POD

As student enter the room, they will have a seat, take out their Problem of the Day (POD) sheet and begin to work on the question on the SMARTboard. The POD allows students to use MP 3 continually based on the discussions we have about the problem each day.

POD: If ab = ba, does 35 = 53? Explain your answer.

I want students to identify the commutative property and tell why it doesn’t apply in this instance. Recognizing the commutative property is an important strategy for writing linear expressions and I need them to know when that property may not apply. This example is literal and we can use this to connect to how it may be misused. Changing the order doesn’t always result in an equivalent expression.

  • Learning Target

The target for the day is also on the SMARTboard each day when students enter the room.  The target for today’s lesson is for students to simplify expressions they are given. SWBAT solve mathematical problems using numeric and algebraic expressions.


25 minutes

The explore section will have students write expressions to represent each step in a number trick. Students will write the expression and perform the operation described. When students reach the final step in the number trick, they will see a pattern emerge. Students will also spend time writing their own number trick to share with a partner. They will write an expression to represent each step in their trick and then walk their partner through the trick to ensure expressions are correct and that the trick works.

As students create their own number tricks, I am anticipating there will be considerable struggle as they try to find a path to the desired answer. As they put steps into the trick they will need to test the trick to ensure they reach the desired result. I want them to think about why certain steps work and why others won't.The process should include reasoning and criticism along with justification about why they couldn't use certain steps.


5 minutes

To leave class, I want students to use theTraffic Light to gauge their comfort level with writing and solving number tricks. I want to know if they understand the connection between the expression and the step in the tricks.