Page 66 - Demo

Lesson 31: Grobby%u2019s Number MachineThrough appropriately playful learning experiences, children should be able to use a range of counting and calculating strategies for a range of purposes.Learning outcomes%u2022 We are learning to use an adding/function machine%u2022 We are learning to apply an operation (addition) to a number, known as an input%u2022 We are learning to predict the number that will come out after the operation, known as the output TasksChildren complete the task sheet by drawing the brick stacks that come out on the right-hand side, from Grobby%u2019s Number Machine.ProcedureAcquire a large cardboard box that will comfortably accommodate a child of 5/6 years. The back end is open so that the child can easily crawl in and sit down. Cut a small hole in the centre of the left side into which a brick or brick stack will be passed in. Cut a small hole in the centre of the right side into which a brick or brick stack will be passed out. On the front of the box, you can hang one of the signs e.g. +2One child enters the box. A second child sits to the left side, near the input slit. A third child sits to the right side, near the output slit. The remainder of the class sit in front of the box. (They cannot see the child in the box or what he/she is doing) Tell the children that this is the %u2018Number Machine%u2019. The number machine will do something to numbers that pass through it, it will carry out an operation. It will perform the same operation on each number that goes in. Let%u2019s tell it what to do (number operation), I want the machine to %u2018add 2%u2019 to every brick or brick stack that goes in. For the machine to know what to do, we have to tell it. For example: Machine, add 2 to every number. The teacher also hangs +2 on the front for all to see. The student on the left holds up 1 brick, says %u201c1%u201d, then passes it into the machine. The child inside takes that brick, adds 2 more to it and passes it out the other side. When it comes out, he/she holds it up and says %u201c3%u201d. Teacher says: %u201c1 brick went in, but 3 came out. What happened?%u201d Quiz/converse with the children: 2 bricks were added to the 1 by the machine. 1 plus 2 make 3, the box added 2. Continue inserting bricks and adding 2, and talking about the process. Record some of the operations in abstract form e.g. 1+2=3, 4+2=6, 2+2=4 etc. Change the instruction for the machine e.g. +3 or +1 etc.Instead of placing the instruction on the front of the box, pass the instruction to the child in the box without the other students seeing it e.g. +3 Pass in 1 brick. Out comes 4 bricks. Pass in 2 bricks. Out comes 5 bricks. Pass in 3 bricks. Out comes 4 bricks. Can they say what happened? What is the pattern? What is operation that is being performed? Pass in 4 bricks, out comes 6 bricks. Pass in 7 bricks, out comes 9 bricks. Ask students to say what they think is happening. A live function machine such as this is a great way to get children engaging with and thinking about number operations. The live function machine makes it all somewhat more immediate, tangible and observable. What other ways can you use Grobby%u2019s Number Machine to explore and problem solve with numbers e.g. engage in subtraction i.e. pass in 4 but 3 come out? Materials A large cardboard box into which a child will fit, with an input hole/tube and an output hole/tube. 2 sets of 6 bricks. 6 signs as follows: +1, +2, +3, +4, +5 and a +6.%u00a064