1. Let's clarify what "7" and "21" represent in your context. 2. If these are results from an operation like multiplication or addition, show the original numbers or equation you are referring to. 3. For example, in multiplication, $7 \times 3 = 21$ explains how 7 and 21 are related. 4. If you provide the original problem or expression, I can walk you through how those numbers were obtained step-by-step.