Final answer:
To find a ratio, divide the first quantity by the second quantity to express their relationship. Ratios often appear in problems that involve comparing quantities or dimensional analysis, where multiples are used to cancel units and express quantities in the desired units.
Step-by-step explanation:
To find a ratio in a problem, you typically divide the numbers. Subtracting, adding, and multiplying are other operations that may be necessary in various steps of a math problem, but to express one quantity in relation to another, you divide. For example, if you have two quantities, A and B, the ratio of A to B is found by dividing A by B to find how many times B is contained within A or how A compares to B.
Ratios can be written like fractions and can thus also be manipulated like fractions. When you multiply fractions, you multiply the numerators together and the denominators together. The ratio can be simplified by finding common factors and reducing them. Dimensional analysis is a technique often used in problems involving units, where the given information is multiplied by known ratios to yield the final units sought (find). This can involve division to cancel out units and to find the appropriate ratios.