This chapter teaches how to compare two quantities of the same kind. Ratio (represented by ':') is used to see how many times one number contains another. When two ratios are equal, they are said to be in Proportion. A major highlight is the Unitary Method, where students first calculate the value of a single unit and then use it to find the value of any required number of units. These concepts are extremely practical for daily activities like shopping, cooking, and comparing speeds, helping students make logical comparisons and calculations.