Dewch i Feddwl Mathemateg (9 i 11 oed) Gwers 4 Graffiau Cryno

# Lesson Plan

Abstract |

Tell the children you went to a farm with some much younger children, where they saw sheep and horses. Show the pupils the cut out horses and sheep from Resource Sheet A. Tell them that your one of the young children said that there were more horses. Why does she think this? (This is because the horses are larger.) |

Episode 1 |

IntroAsk them to think about how we could show how many of each there are to prove to the children that there are more sheep. Have the multi-link to hand and build towers to represent the different animals. Ask how we could use this to show that by more we mean the number of each not their size. Consolidate the fact that here 1 block = 1 object/species. Show them Resource Sheet B and ask what they can see. Categories the species/objects we are dealing with here eg pets, farm animals, vehicles, people etc. The number of categories is not important, but a smaller numbers is best in order to leave time to focus on the challenge in the task, eg farm animals instead of chickens, sheep and horses. Ask them to construct multilink towers to show all of this information so we can compare the numbers of each just like we did with the farm animals. |

Group DiscussionThe children work in groups to construct columns (eg multilink towers) to represent Resource Sheet B. Offer the children a choice of multilink or A4 centimetre squared paper to show their findings. Give the children free rein to do this in whatever way they choose, as many will try to build massive towers to represent the number of people. |

SharingDiscuss the difficulties the children have had. Focus upon the fact that if 1 block = 1 object then we have problems. Draw out those who have considered or used a 1: many ratio i.e. 1 block = 5 objects as a way of making sensible block graphs. Discuss the benefits of using multilink or representing it on squared paper – which is best and why? |

Episode 2 |

IntroShow the children Resource Sheet C and tell them it is about the height of a new cucumber plant on the farm for 24 months after it was first planted. Explain that the farmer wanted to know how quickly and how high to expect the plants to grow. Ask the children to draw a graph to show the information in the table using A4 centimetre squared paper. |

Group DiscussionThe children work in groups using A4 centimetre squared paper to represent the information on Resource Sheet C. They will find it impossible to represent the numbers one-to-one and will have to experiment with different ways of representing the numbers. Encourage the children to annotate representations that do not work, rather than throwing them away, so that they can be discussed at the end. Some children may still use bar graphs for this, but others may decide to use a line graph. |

SharingDiscuss the different ratios the children have tried and the ratios that did not work. Discuss the fact that a scale of one to ten (ie one unit up or along the axes) means we can fit the numbers onto the sheet but that the bars are quite small. However, when we use a scale of one to five (ie one unit up or along the axes), we can fit the numbers onto the sheet and the graph is very clear. Compare the bar and line graph (have one to hand in case nobody draws one) and explore what additional information a line graph might show the farmer. Ensure that the word axis is used and understood in this episode. |

Episode 3 |

IntroShow the children Resource Sheet D and tell them it is about the heights of two of the adults who accompanied the children to the farm (alternatively you can add the names of two known adults from the school to the table). Explain that these two adults want to compare the way they grew using a graph. |

Group DiscussionAsk the children to plot the results for both children onto the same set of axis. Children trying to draw bar graphs will find this difficult to represent. Encourage children who decide to draw line graphs to show the two sets of data. |

SharingDiscuss the different ways children have tried to represent the information and the difficulties with representing two sets of information using a bar graph. Compare bar graphs produced to line graphs and discuss which represent the information more clearly. |