Number: Taking handfuls
View Sequence overview10 is a useful benchmark to quantify and compare larger collections.
Each group
A collection of at least 40 counters
At least 10 tokens (e.g. cubes, teddy bear counters)
Each student
Close to 20 Gameboard, ideally printed on A3 card
Build
Revise: 10 is an important number in our number system. It is a very useful number to compare larger collections.
Share with students that they will use 10 as a benchmark number in a game. Explain how to play Close to 20 in pairs:
- Both players take a handful of counters, trying to get as close to 20 counters as they can without going over.
- Each player arranges their handful onto their gameboard to show how many counters they have.
- Any player who has more than 20 counters is out for this round.
- The remaining players compare their collections:
- Whoever is closest to 20 is the winner and collects a token.
- If both collections have the same number of counters, both players collect a token.
- Anyone who gets exactly 20 counters collects a bonus token.
- The first player to collect 5 tokens wins.
Students play Close to 20.
Gather the students together for a whole class discussion at the end of the game. Discuss how students used 10 to compare who had more or less. For example:
- "I have 10 and 6 more, you have 10 and 7 more. You have more than me."
- "I have 2 less than 2 tens. You have 3 less than 2 tens. I have more than you."
10 as a benchmark
We designed this simple game to build students’ skills in using 10 as a benchmark number. Students name the number in their collection in relation to 10 and the winner is determined by the person closest to 20.
It can be difficult for students to determine who is closest to 20 if one player has fewer than 20 counters and one player has more than 20. For this reason, we chose to eliminate players who had more than 20 counters in their collection.
We designed this simple game to build students’ skills in using 10 as a benchmark number. Students name the number in their collection in relation to 10 and the winner is determined by the person closest to 20.
It can be difficult for students to determine who is closest to 20 if one player has fewer than 20 counters and one player has more than 20. For this reason, we chose to eliminate players who had more than 20 counters in their collection.