Thirteen point six is a number with a decimal point within 100. 1 of 13 is a decimal digit of 1, 3 is a digit of three 1, and 6 to the right of the decimal point is six zeros.1. If 13.6 inch equals 34.544 cm, because 1 inch equals 2.54 cm. Every time the decimal point moves to the left, the original number decreases by 10 times. In other words, the original number is divided by 10, and every time the decimal point moves to the right, the original number is enlarged by 10 times. It can also be said that the original number is multiplied by 10.

Decimals and mathematical symbols will be learned in Unit 7, Book 2, Grade 3. In decimal, they are used to separate the integer part from the decimal part. Although the decimal point is small, it plays a great role. We can't ignore this little symbol at any time. Because of this humble mistake, mankind has brewed one tragedy after another. It can be described as "a thousand miles away." For example,100x13 =1300,100x13.6 =1360, so the difference between them is 60, which shows the importance of decimals.