Target 100 – a 2 Digit by 2 Digit Addition & Estimation Game
Addition Game = Target 100 is a simple Math card game designed to have students practice estimation and 2 digit by 2 digit mental addition strategies.
What you Need:
– 1 set of playing cards (1 to 10) for each player
– 3 or 4 players
– Paper for recording sheets
– A way of timing one minute e.g. stopwatch, timer app, egg timer, etc (optional)
How to Play:
1. Dealer shuffles all the cards as a single deck, gives 6 cards to each player face down & starts the timer.
2. Players quickly turn their cards over and choose 4 cards with the aim of making 2 two-digit numbers that when added produce a total as close to 100 as they can get.
3. Each player lays their numbers on the playing surface for all to see.
4. The player who has the total closest to 100 wins a point for the round. In the event of a tie, each player receives a point.
5. Players record their algorithm at the end of each round.
6. Dealer reshuffles and deals the cards each round.
How to Win:
Get closer to the target number than your opponents.
Before the Game:
– Discuss & experiment with adding numbers right to left & left to right.
– Discuss ‘helpful’ and ‘unhelpful’ self-talk.
– Explore efficient ways to add two digits by two-digit numbers mentally.
During the Game:
Ask, ‘What strategies do you think you need to work on to do better at this game?’
Ask, ‘What strategies have you put in place to ensure you learn during this game?’
Teacher – ‘When I was learning this stuff I found… (insert favorite strategy) helped me. Try it now and see if it works for you.’
After the Game:
– Have students record – What new skill did you practice today? What do you feel you need to work on as a result of playing this game? What went well for you in this game today?
Stuff to Think About:
– Providing recording sheets denies students valuable thinking and learning opportunities.
– Ready-made recording sheets deny students the opportunity to experiment with organizational and recording strategies.
Recording Sheet Production:
– Provide students the opportunity to develop their own recording sheets. Name, Number of Rounds, the algorithm produced, answers to algorithms & totals need to be included.
– Emphasise Function over Form i.e. Make it work first then make it look pretty.
– Students trial other students’ efforts. Provide opportunities to discover better/more efficient recording methods.
– Discuss traditional ‘neatness’ in the light of Function / Form/legibility/ease of communication and getting the job done.
- Play the game with teams of 2 or 3 students.
- Change the amount of time available for making a decision about number choice.
- Change the number being aimed for.
- Change the number of cards each player is dealt.
- Deal 8 cards and aim for 1000
- Make up your own variations