Six Plus

Years K - 6

Summary

Demonstrate this simple game with the help of a child then set them to work in pairs looking for their partner's secret number. Some children will soon be asking if they can extend the game. Suitable for threading.

A visiting teacher suggested to me that this was a great activity. When he described it I couldn't believe it was anything special so I asked him to demonstrate with my Year 1 class. I was worried when not knowing the class, he chose my weakest maths student as the helper. Ahmid worked out the problem first shot and I nearly died.

Materials

  • One calculator for each child

Note: This investigation has been included in Maths At Home. In this form it has fresh context and purpose and, in some cases, additional resources. Maths At Home activity plans encourage independent investigation through guided 'homework', or, for the teacher, can be an outline of a class investigation.
  • Visit the Home Page for more Background.
  • For this specific activity click the Learners link and on that page use Ctrl F (Cmd F on Mac) to search the task name.

Procedure

  1. Arrange the children in a circle on the floor. Each child has their calculator.
  2. Ask for a person to help you show a new game to the children. Bring them to the front beside you.
  3. Say something like …
    Ahmid I want you to help me teach the children a game. I am going to press 6 and plus on my calculator … then I am going to press one other number, but [… be mysterious here …] I am not going to tell you what it is.
 

Content

  • addition facts beyond 10
  • addition facts to 10
  • equations: creating/solving
  • estimating number
  • multiplication
  • operations - whole number
  • problem solving
  1. Press 6 + 9, for example, and show your calculator screen to the helper.
    This is the answer I got. Now you have to find out the secret number I pressed. Start with 6 and + because you know that's what I did.
  2. It is very likely that the helper's face will screw up in concentration and that they will enter the correct number first time and thereby match their calculator display with yours.
    Great thinking. You get one point. Now you give me one.
  3. When the helper offers you a problem deliberately 'think hard' and don't enter the correct response first time.
    Oops. That's not the same as your screen. That's one point to me.
    This last statement is likely to lead to quizzical looks around the class, but proceed without comment.
    Hmm, let me think again. 6 + … Ahh I know.
    Press the correct button and show the calculator to the helper for confirmation.
    That's two points to me … and you win!
  4. Have a discussion about why Ahmid wins with the lower score …
    He did better thinking than you.
    … and invite the students to play the game in pairs.
The children will fairly naturally move from 6+ to other questions like 9+ and 4+, and before long there will be one pair who ask: Can we use two figure numbers?

Using Six Plus

Consider using the game for short periods every two or three days over an extended period and letting it expand naturally as the students move it on. After a session, sometimes make a point of discussing the mental strategies the students are using.

Sometimes too, move among the pairs and interrupt their game long enough to challenge them to demonstrate the problem they just did by using the yellow/blue Poly Plugs.

6 plugs + 9 plugs
6 + 9 = 15

Another way to approach this modelling of addition is to play Six Plus with Poly Plug. Begin with a red board that has the middle column masked so that one player is on one side with two rows of five spaces and the other player is on the other side with the same.

  • Player A enters 6 + on the calculator. They also plug in 6 yellow plugs.
  • Player A then continues the Six Plus game as above by entering a secret number followed by = and showing the result to their partner.
  • Player B plugs in what they think is necessary to reach the screen number and checks the total of plugs in two ways.

Extensions

  1. When the students are familiar with, and practised in, the game, written missing number questions like those below can be successfully introduced as a way of indicating the 'secret number' in the game.

  2. Exactly the same approach works with Six Times and it is remarkable how willingly the variation is played, even by those students who have developed automatic response.

  3. Try 20 Minus. The students will soon expand this to 99 Minus and take away two digit numbers.
This pair has changed the game to 9 Times and are using 2 digit numbers.

What makes '6 +' different from 6 + Blank Box = 15?

Mathematically the two presentations are the same. Why is that children will do dozens of these 'sums' as part of the game, but baulk, and even think they can't do them, when ten of these 'sums' are presented on a worksheet or from a textbook?

Teachers have suggested that the following features make the difference:

  • Empowerment - students are in charge of the numbers.
  • It's yours - you are involved.
  • Recreational - this is 'stuff we can have fun with'.
  • Learning together - student/student and student/teacher - everyone has a part.
  • Self-checking of the reasonableness of answers.
  • Provides reason to learn the skill - ie: to play the game better.
  • Immediate response.
  • Non-threatening.
  • Mathematical conversation.
  • Writing doesn't get in the way.
  • Potential to link concrete, symbolic and personal recording.


Return to Calculating Changes Activities

Calculating Changes ... is a division of ... Mathematics Centre