1. This calculator is for the building trade. It has two main functions.
2. It can calculate how many blocks or bricks are needed for a particular size of wall.
3. It can calculate the volume of concrete needed for given dimensions and depth.
4. Not only can the rule work in feet or metres, it can also convert from one set or units to the other.
5. One interesting feature of this rule is the way two complementary but different functions have been included on the same rule.