An artificial Christmas Tree needs to be assembled layer by layer by attaching branches to a central column. There is a top piece which has no individual branches but is attached on the top of the column. This table shows the branches on each layer.
Each branch takes 30 seconds to attach and shape, and the top piece takes 4 minutes to attach and shape on its own. How long will it take to assemble the Christmas tree ready for decoration?
Students enjoy this seasonal video, and it encourages them to link seconds to minutes, and to add up multiples of time. It works as a festive starter and normally takes a class 3-4 minutes to complete. It is often beneficial to discuss different approaches to the ’30 seconds each’ part of the problem. Extensions always work well too.
Teachers could extend the learning by considering:
- If the top piece requires 25 baubles to decorate it and each branch requires 3 baubles, how many baubles are needed to cover the tree?
- It takes 75 minutes to add lights and decorations. If the owner started at 4:00pm, at what time would the tree be finished?