# Target Number Game

## Curriculum Goal

#### Primary: Number Sense

• Estimate the number of objects in collections of up to 50. Verify the estimate by counting.

## Context

• Whole class demonstration. Students then work independently or in pairs.

## Materials

• Several containers filled with small objects that are easy to count (e.g., buttons, beads, etc.)
• Recording sheet (Appendix A)
• 100s chart for reference

## Lesson

• Introduce the concept of estimation by discussing real-life examples of estimation (e.g., estimating how much money to bring to the grocery store, how much shampoo to put into your hand to wash your hair, etc.).
• Invite students to think about moments they may have used estimation and share these with a classmate.
• Demonstrate estimation activity to the whole class.
• Take 10 items from the container in a way that the students can see each piece being added to the next.
• Model how you might think about the 10 cubes: they take up a greater amount of space than when there was just one cube. If you were to hold them, they would be heavier.
• Ask students to pick a number between 15 and 30. Explain this number is the “target number.” Their goal is to scoop up this number of items without counting them out.
• Model how they scoop up the blocks and tell them whether you think you’ve managed to collect the correct number. How close do you think you are?
• Count out the first try and compare the collected number with the target number by asking students to decide whether you gathered too many or too few.
• Have students do the activity independently or in pairs, making sure they take turns recording and estimating.
• Assign number ranges (e.g.,15-30) for students depending on what you think they can manage, but do not exceed 40.
• Instruct students to record the first and second try, as well as whether there were too many or too few.
• Emphasize that the goal is to get close to the target number, rather than the exact number.
• Circulate and ask questions to make students’ thinking explicit. Sample questions:
• What did you do to try and get closer to your target number?
• Just by looking, how many do you think there are?