Red Board of the Day Years 2 - 5

Summary This activity could be thought of as a visual/concrete variation of Number Of The Day. Certainly the two can work well together. The teacher creates a board such as the one in the photo and shows it to the children. Each child (or pair) them makes the same board. The challenge is in not only finding how many blue or yellow plugs there are in the room, but in finding more than one way to find this out. Suitable for threading. Materials One Poly Plug and one calculator per person (or pair) and one for the teacher Recording paper or maths journal or Poly Plug Paper

Procedure Today I want you to plug in your red board to look just like mine. Choose a layout which includes an array (to encourage multiplicative thinking) and a few other plugs. Use the two colours to indicate these two sets of numbers. Assuming you have 27 children in the class there will now be 27 copies of your board around the room. Imagine I ask ten of you to come out to the front with your board. Write 10 students on the whiteboard as you speak. It is also a good idea to 'act out' where these imagined students would stand - One here, ...one here, ...here, ...here, ...and so on. This helps students visualise their friends standing with the boards in front of their chests. Your challenge is to find three different ways to work out the total number of yellow and blue plugs there would be at the front. Don't count my board.

Content addition facts beyond 10 addition facts to 10 complementary addition exploring large numbers group (or skip) counting mathematical conversation multiplication - array model multiplication operations - whole number order of operations recording - calculator recording - written subtraction times tables using brackets visual and kinaesthetic representation of number

With their partner's board, children will have two boards they can see - perhaps four if your tables are arranged that way - but 'ten at a glance' is outside their view. Of course one valid way of calculating is to get ten boards together on the floor and count. However, the focus of the activity is on the mathematician's question:

Can I check it another way?

For the picture above, some possible ways to reason are:

• 9 yellow and 1 blue on a board make 10, and there are three other blues. So the total is 10 x 10 + 10 x 3 = 130.
• 10 lots of 9 yellow = 90 and 10 lots of 4 blue = 40, so the total is 130.
• My partner and I put our boards together to make 18 in the middle. So there would be 5 lots of 18 + 5 lots of 8 and that's 130.
• You don't need to worry about the yellow and blue. There are 250 plugs altogether in 10 boards. There are 12 not plugged in each board, so that's 120 not plugged. There must be 130 plugged.

• Each board has 4 + 9 so it's 10 lots of 4 + 9.

I make sure this sort of problem does comes up. It helps to confirm the importance of checking another way, refines interpretation of the order of operations and the need to look for 'bracket situations', and it leads into discussion of how these situations can be evaluated with a calculator. We go on to talk about recording steps towards the answer and using the memory buttons.

Extensions

• Sometimes ask students to record the plug picture and their methods of calculating.
• Extend the question to ask how many plugs have been used in the whole room.

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