Fractional application problems often involve two or more quantities, and we often compare and analyze one of them as the standard quantity, that is, the unit "1".

Some of the key sentences of two kinds of quantitative comparison are "bi" sentences, and some are not "bi" words, but "Zhan", "Shi" and "quite" with directional characteristics. The quantity after these words as the standard quantity is the unit "1".

Some topics are not the relationship between the whole and the parts, nor the comparison of two quantities. At this time, it is a headache for students. Don't be afraid, you just need to upgrade the original quantity and present quantity of text information in the topic into familiar words with "bi" and analyze it! In this process, we can also use the method of line segment diagram to assist understanding.