We can start with the meaning of the score, and we can explain it from the block and synthesis activities. When a whole (reference quantity) is divided equally, the quantity that gathers some of it is called "component", and this "component" is expressed or recorded by "fraction". For example, 2/5 refers to the "component" in which an integer is divided into five equal parts and then aggregated into two halves. When the whole is divided into 10, 100, 1000, etc. Use another method to record the weight at this time-decimal. For example,110 is 0. 1, 2/ 100 is 0.02, 5/ 1000 is 0.005 and so on. The "."is called the decimal point, which is used to separate the integer part from the decimal part that cannot form an integer. Integers that are not 0 are called decimals, and those that are 0 are called pure decimals. So the meaning of decimals is part of the meaning of fractions.