What Are The Functions of Tape Measure?

Tape measure is a very common tool in life, but when we use the tape, it is found that many of its design is difficult to understand. In fact, every seemingly strange design is useful, but we do not understand their real function. If you are really familiar with the tape function, let's talk about it.
First, the hook on the hook and the magnet have underestimated function. The function of the magnet is that when there is a long distance to the measurement, it is not necessary for a person to hold a foot hook if there is a piece of iron that is just sucked with a magnet.
Second, the figures on the ruler have the function of marking. Not all of the ruler has a number, such as cost-effective tape may not have this flag number.