Addition & Subtraction Game to 20
Addition & Subtraction Game to 20
Math Games – Addition & Subtraction Games – Contig Jr.:
Contig Jr is a Math game that focuses on mental Addition & Subtraction skills.
Game in a Nutshell:
Students throw 3 dice then apply Addition &/or Subtraction to the numbers thrown to achieve a total. Students place a counter over these numbers to earn points.
What You Need:
1 Contig Jr game board
16 counters *
* (NB I like to use colored blu tac or play dough so counters don’t get knocked around)
Who Goes First?
Each player rolls the three dice. The player with the lowest sum goes first.
How to Play:
1. Player 1 rolls the three dice and applies Addition &/or Subtraction to the numbers rolled to create an algorithm.
2. Player 1 says the algorithm aloud complete with the answer. They then place a counter on the board over the answer.
3. Player 2 repeats Steps 1 & 2.
4. Play continues in this turnabout fashion for 8 rounds.
How to Earn Points:
Players earn points when they cover a number on the board which is adjacent (next to either vertically, horizontally or diagonally) to an already covered number. One point is scored for each adjacent counter.
NB I use this as an opportunity to teach and reinforce tally making.
What if a Number is Already Covered?
Players may not cover a number already covered.
The Passing Rule:
When a player rolls the dice but cannot produce a number not already covered they must pass. Players can ONLY pass if there isn’t an available number on the board. the player with the highest cumulative score wins.
Challenging a Mistaken Pass:
If a player passes and another player sees this is a mistake they can challenge the pass by saying ‘challenge’. The challenger then outlines their answer and covers the number and earns the points.
NB the challenged player receives no penalty for this and the play continues in the usual.
How to Win:
A cumulative score is kept for each player. At the end of eight rounds, the player with the highest cumulative score wins.
Addition & Subtraction Game – Low Color
Before the Game:
– Discuss and explore the strategies students use to arrive at an answer when adding three dice together.
– Explore and Discuss – ‘A math strategy is good if it is accurate AND efficient’. Many strategies will give the right answer but are very slow.
– Any students who are still counting individual pips will benefit from a small group tutorial session on subitizing
– Discuss and demonstrate the strategies of Counting Through 5 and Counting Through 10.
– Demonstrate how knowledge of Doubles and Near Doubles can help speed up the calculations.
During the Game:
– Monitor and take notes of the strategies students are using to add the dice. e.g Who is counting on? Who is counting pips? Who is counting under their breath (sub-vocalizing)?
– Note which students are finding this version of the game ‘too easy’ and swap them to the more advanced version of Contig available on for free on the website.
– Encourage subitizing as an effective and efficient strategy to make the game flow.
– Sit down beside a group and say, ‘I find Counting Through Ten helps me get the answers faster.’ Then demonstrate it. ‘I’d like you to try it for a while and I’ll be back in about 5 minutes to see how you are going with it.’
– Be sure to remind the groups of the skill focus for the game.
After the Game:
– Teacher uses the notes taken during the gameplay to work out small group focuses and plan accordingly.
– Think Pair Square – What do you like about playing this game?
– Think Pair Square – What do you dislike about playing this game?
– Class discussion – ‘Where might this sort of mathematical thinking be used in the “real world”?’
– ‘I can’t remember what round we are up to’ is a commonly heard phrase when playing this game. Have the students design a recording sheet to ensure these words are never uttered 😉
– Have your students teach this game to another class.
Possible Journal Reflections:
– While I was playing this math game I noticed ______
– I am still a little confused about ______
– During Math today I felt ___________ because _______
– What strategies do you think you need to do well at this game?
– What Math ideas did you learn today?