Purpose
Measurement 1 Vocabulary: • Length • Longer • Shorter • Same
Students will measure using uniform objects
Vocabulary Length, Longer, Same, Shorter
Length When using cubes to measure the lengths of objects, we would consider each cube as having a length of 1 unit rather than trying to use millimetres, centimetres or metres. Have students estimate and then measure the lengths of a variety of objects using the cubes. Ask the students if it makes a difference to the count if they lay the cubes side-by-side or join them together.
In the instances above, students can see that the spaces between the cubes can make the line of cubes seem longer. If the cubes were placed so that they touched side-by-side but with no ‘plugs’ between them, then there would be little difference in the overall length of the two lines of cubes. The early stage of working with the attribute of length involves students placing two objects side by side and making a direct comparison. This ties in to the subtraction activity earlier in this book but here the emphasis is on which of the two sticks is longer, and by how many cubes. Fundamentally when measuring we want to answer three questions: •
Which is longer?
•
How long?
•
How much longer?
The yellow stick is 1 cube longer than the red stick. The red stick is 1 cube shorter than the yellow stick.
© P. Swan
35
Cubes
Statistics
Purpose
Students will use cubes to determine the mean of a set of numbers. Students will use cubes to create graphs.
Vocabulary Bar Graph, Data, Mean, Pictograph, Side-by-side bar graph
Making a Pictograph (Pictogram) Students close their eyes and, with two hands, scoop out as many cubes as they can. They then sort them into groups according to their colour.
Finding the Mean Using Cubes Students make a stick of cubes as long as the number of letters in their first name. For example, Ray would have a stick 3 cubes long; but Josephine’s stick would have 9 cubes. Groups of students line up their sticks, in order from shortest to longest.
Emma
Bella
Joshua Natalie Benjamin
Students then move cubes from the longer sticks to the shorter ones, trying to end up with them all the same, or nearly the same, length. In the case above, two cubes would be moved from Benjamin’s stick and added to Emma’s and one cube moved from Natalie’s stick to Bella’s. This would result in all sticks being six cubes long. So the mean (average) length of the five students’ first names is six. Where the results do not work out as neatly as the above case, an approximate mean (average) number could be reached. For example, if the names were Ian, Karen, Bonnie and Christopher, the cubes could be moved so that all sticks were six cubes long with one cube left over. So the mean number of letters in their names is a little over 6, or exactly 6.25. © P. Swan
41
Cubes