Plug Lines Years K - 6

Summary Everyone in the group removes the top row of red plugs from their red board and plugs the gaps with yellow. Now we put them side by side and make a long line of yellow plugs. This is an 'empty' number line. Now there is lots of pattern, ordering and number work that can be investigated. Suitable for threading. Integrate this activity with Making Number Lines. Materials One Poly Plug set each, or per pair, depending on the size of the group Small cards (about the width of a plug space) and marker pens (An alternative is strips of scrap paper the width of a red board to place on the board beneath the plug line. Add arrows when necessary to point to chosen yellow plugs and write chosen numbers under the arrows.)

We made a pattern, but we had to put on another child with a blue sun hat to finish it. PrePrimary, Holy Rosary School, Derby A story shell was added to the activity in this classroom.

Procedure If each child plugs in one row of five yellow plugs... then all the children line up their boards like this... we have created a reasonable representation of an empty number line.

Content 1:1 correspondence counting decimal interpretation group (or skip) counting number line - ordering, operations numeral recognition odd & even numbers pattern generalisation pattern interpretation pattern recognition recording - calculator recording - written visual and kinaesthetic representation of number

The spacing between every point is not exactly the same because of the double width where two boards meet, but this is actually a positive because it keeps a counting by 5/10 image in the background.

	We are making a line of yellow plugs. What happens if we put all our red boards together? Kindy group (4 year olds) at Neerabup Primary School.
Then I want to count them all...	...but I might need a little help.

Pattern by Cardinal Number (Quantity)

Amber, on the first board, leave the first two yellow, then turn over the next three to make them blue.
Alphonse, you do the same to the next board.
Now Fen, you do the next one...

When all the boards have been changed ask questions like:

How many blue plugs are there?
How did you work that out?
Can we check it another way?
How many yellow plugs are there?
How many plugs are there altogether?
Let's count in groups of colours as I touch the end one each time ... 2, 5, 7, 10, 12, 15, ...

• You have your calculators to use as well.
• Counting can be recorded on the whiteboard too.
• You might find two patterns in the recording. eg: ² \ ₅ / ⁷ \₁₀ / ¹² \₁₅ ...
• If you are working with older children, this could introduce:
  
  • Task 10, Find My Pattern from the Mathematics Task Centre
  • Maths300 Lesson 117, Colour Spots on a Number Line

We are going to turn over every fourth plug and make it blue. You start Fong....

Mmm, there are two blue ones on the same board here. I wonder which board that will happen on next?

How can we check that hypothesis?

Blank & Empty Number Line Problems

The idea of all these problems is that you write cards to point at two plugs on an otherwise blank number line and students have to work out what the other plugs represent. Change the cards to change the difficulty of the problem. Decimals and fractions can be encouraged in this way - negative numbers too if you want to.

Examples

What numbers could the other plugs be?

Notes: If the equal spacing 'glitch' at the board edge annoys, simply overlap the boards a little. Lining the boards up along the whiteboard ledge means that cards aren't needed because the arrows and numbers can be written on the board. Using a whiteboard ledge plug line is also a way to bridge into students sketching their own blank number lines. First I want you to find a way to quickly sketch the number line part of this display in your journal. Show and discuss the various suggestions. Now I am going to show you the positions of two numbers on this number line. You have to work out the numbers in between. If it helps you, you can come up and use the display. Otherwise, use your diagram and explain your thinking underneath. As success develops, the next bridge might be to encouraging students to begin with an empty number line (a line segment with an arrow head at each end) to which they add their own 'jumps' and numbers to help solve problems. Plug Lines has strong links to Move Around. In Move Around the students themselves become the points on an empty number line which is one side of the basketball court or similar multipurpose room or playground space. Move Around notes include a link to a Cube Tube video of one class using it outside. Maths300 lessons built around a number line concept include: Lesson 33, Fraction Estimation Lesson 117, Colour Spots on a Number Line Lesson 182, Fractions to Decimals (on a rope!)

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