Describe one situation where an approximate answer is good enough, and one where you would need a very exact value.
An approximate answer is good enough in the early stages of reasoning or when making a rough estimate to check whether a result is reasonable or impossible. For example, estimating the amount of rice needed to feed a family for a month or the volume of air breathed in a day does not require exact values.
Describe one situation where you would need a very exact value.
A very exact value is needed when building more complex models that require greater accuracy. For instance, in a cricket shot, a complex model adding extra details for greater accuracy would need exact values for important quantities like the mass of the ball, its speed, and direction.
Explanation
The textbook context explains that exact values are not always necessary in the early stages of reasoning; approximate estimates help build intuition and check if a result is reasonable (e.g., estimating rice for a family or air breathed). However, as we build more complex models for greater accuracy, exact values become necessary for important quantities, such as the mass, speed, and direction of a cricket ball.