After brainstorming and experimenting, we got out tape and some string. We invited the students to cut a length of tape or string they thought would be long enough to reach around the centre of the pumpkin. We reviewed estimation and reinforced the idea that the length of string needed to be close, but not necessarily perfect. Re-cuts are totally permitted! After arranging the pumpkins by size, we could decide together whether we would need a longer or shorter piece of string to go around the next pumpkin. We also used tape measures to predict and measure the pumpkins’ circumferences. Finally, the children made chains of coloured links the lengths of the strings. They also build stacks of unifix cubes the same heights as the pumpkins.
Through this investigation, the children showed an excellent awareness of non-standard measuring devices such as string, links, and cubes, as well as standard measuring devices such as rulers and tape measures. They also demonstrated clever strategies for using these tools. Bravo!