“We have been using ten-frames and number lines as tools to help us with addition and subtraction problems. Today we are going to use what we know about addition and subtraction to play a game called Goal Number.”
Display a twenty-frame (M-1-3-3_Twenty-Frames.doc). Take a few minutes to let students make observations about how the numbers are organized if they have not used a twenty-frame recently. They should notice that a twenty-frame is made from two ten-frames. They should see the darker lines which represent a 10 or a 5.
“What do you notice about this twenty-frame tool?”
If students don’t notice what you are looking for, use prompting questions such as: “How many squares are on the top row? How many are to the left of the line? How many are on the right?”
Ask students, “If you had 4 chips on the twenty-frame, how many more would you need to make 11?” Model what they talk about on the twenty-frame.
Explain to the class that today they are going to practice reaching a goal number. “If you had the numbers 4, 3, 5, and 0; which numbers would you use to reach a goal number of 7?”
Have students talk with their groups of four or five about what strategies they might use to reach the goal number.
“Talk with your group about what strategy will work best if the goal is to use the most numbers/cards possible?” (Possible strategies: Use the smallest numbers first, combine addition and subtraction, etc.)
After a few minutes ask groups to share their strategies. Record them on a larger version of the recording sheet (M-1-3-3_Goal Number Recording Sheet.doc).
“Today in pairs you will play several rounds of the Goal Number game. You will record your final equation for the strategies you choose and the points you earn.”
Have one partner get the numeral cards (M-1-3-3_Numeral Cards.doc) and the other partner the recording sheet (M-1-3-3_Goal Number Recording Sheet.doc) and find a spot to play. Allow enough time for students to play several rounds or to allow you enough time to talk with each partner pair at least once.
When the time is up, gather the students and have them share their total number of points for the rounds they played. Discuss strategies children used to get the most points. Also discuss which numbers were the hardest to reach and why they think that was the case.
Optional: Create a class poster of “high points” for the game.
- Expansion: Change the numbers for Goal Numbers to meet the needs of your students. Have numeral cards up to 50 or 100 for advanced learners.
- Workstation or Small Group: Provide number lines for students who have difficulty with twenty-frames or mental strategies (M-1-3-2_Number Line.doc). Have students circle the goal number on the number line, then experiment with the numeral cards to see how to best reach that goal number.