10 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
Explain to students 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.
Learning Goal
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.