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Going down

This is a level 2 number activity from the Figure It Out series. It relates to stage 5 of the number framework. A PDF of the student activity is included.

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Tags

  • AudienceKaiako
  • Learning AreaMathematics and Statistics
  • Resource LanguageEnglish
  • Resource typeActivity
  • SeriesFigure It Out

About this resource

Figure It Out is a series of 80 books published between 1999 and 2009 to support teaching and learning in New Zealand classrooms.

This resource provides the teachers’ notes and answers for one activity from the Figure It Out series. A printable PDF of the student activity can be downloaded from the materials that come with this resource.

Specific learning outcomes:

  • Add and subtract one-digit numbers from two-digit numbers.
     
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    Going down

    Achievement objectives

    NA2-1: Use simple additive strategies with whole numbers and fractions.

    Required materials

    • Figure It Out, Levels 23, Number, "Going down", page 9
    • calculator
    • dice
    • different coloured counters for each player
    • classmate

    See Materials that come with this resource to download:

    • Going down activity (.pdf)

    Activity

     | 

    This is a calculator version of the game Num, which is played with counters. Students are likely to play the game without a strategy to start with. They may realise that if they can finish their turn with the window showing three, they can win, no matter what move their opponent makes.

    For example:

    Two arrows point between 3, 1, 0. The first arrow captioned "partner takes away two", and the second "you take away one."
    Two arrows point between 3, 2, 0. The first arrow captioned "partner takes away one", and the second "you take away two".

    Similarly, if they can finish a turn on six, they can bring the total to three in their next turn and go on to win the game (no matter what their opponent does). If they finish a turn on nine, they can bring the total to six, and so on.

    The game can be adapted by allowing each player to subtract one, two, or three when it is their turn. This will require a winning strategy that aims at multiples of four instead of three.

    This is a game of chance that requires students to subtract single-digit numbers. Students should perform these calculations mentally. As an extension, data could be gathered about how many throws it usually takes to reach the bottom row. This data could be gathered on a dot plot as students play the game in groups:

    A dot plot recording the number of throws of the die in a pyramid game with the x-axis showing a range from 8 to 20.

    The distribution could be explained by looking at the difference between the numbers on the bottom row and the top number, 50. The issue would then become:

    • How many throws do you need to take away about 40?

    Note that the dice average is 3.5, so 40 ÷ 3.5 ≈ 11 is a good indication of the median number of throws needed.

    Game 1

    Calculator game.

    Game 2

    Pyramid game.

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