Learn what a tape measure looks like. The tape is marked off in inches and fractions of inches. Each inch has a number next to it, so measuring whole numbers is easy. Each foot usually has either the number of feet or the inches in a more pronounced number so it can be easily seen.
Place the tape measure on what you want to measure. There is a little hook at one end that can grab the edge of a table, a slab, a board, or anything that needs measuring. If there is no place to grab onto, you need a second person to hold the end in place. Unroll the tape to the other end of what you want to measure. You will see the measurement at that end. It will be in feet, inches and fractions of inches. There are marks on the tape that will tell you exactly the size of what you are measuring.
Learn fractions. If you do not know fractions, you cannot read a tape measure. Between each inch number there are lines on the tape measure. Each of those lines is a measure of distance. The longest one in the middle tells you it is halfway between the two inch marks, so it denotes 2 and 1/2 inches or 5 1/2 inches or whatever two inch marks it is between. Between the whole number and the half inch marks, you will find a quarter inch line. It is longer than the other lines, but shorter than the 1/2 inch line. If you see it next to the lowest inch marking, that means your measurement is X and 1/4 inch. If it is between the half inch line and the larger inch number, your measurement is X and 3/4 inches. The other lines on the tape measure tell you eighth inches and sixteenth inches with the eighth inch line being smaller than the quarter inch line, but longer than the sixteenth inch line. Rarely do you find a 32nd inch line. The tape would get too crowded with lines.
Know the importance of reading tape correctly. If you are building a house or simply measuring a room for dry wall, you must read a tape correctly or you will waste building material. Simply seeing and trying to measure by reading 6 and three little lines will not allow you to measure properly. Know fractions and how they are marked on the tape measure.