Determine quantities and numbers – an issue that is already relevant at primary level. For getting started in determining numbers, one should use regularly arranged objects like windows on a (high-rise) building, paving stones on a sideway or stones at a wall.
When determining windows on houses, in many cases you can count the number of windows per row and the number of rows and get the result by multiplication. It is important to make clear whether you ask for windows or window panes, and whether all the windows of the building are relevant or, for example, only windows on the southern front.
For walls and rectangular pavings there are several possibilities:
1. One determines the number n of the stones per 1m² and projects that to the total area A.
2. The length and height of the wall are determined in “stone units” and one counts the number of stones in length l and in width b.
The level of difficulty increases when deviating from rectangular areas and e.g. asking for circular arranged stones. In addition, it can be difficult to determine the number of objects in which the regularity is interrupted in some places and one is forced to choose special solution methods.
You will find a detailed overview of our generic tasks on Determining quantities in the deposited PDF document.
