| No. | Concept | Description | Example |
| 1 | Direct Proportion | Two quantities are directly proportional if an increase (or decrease) in one causes the other to increase (or decrease) to the same extent. | Cost is directly proportional to the number of articles. (More Articles, More Cost) |
| 2 | Indirect Proportion | Two quantities are indirectly proportional if an increase in one causes the other to decrease to the same extent, and vice versa. | Time taken by a car is inversely proportional to the speed. (More Speed, Less Time) |
Note: In solving problems by the chain rule, you should compare every item with the specific term that needs to be found.
