Concept 6

Perform simple quantitative reasoning using provided data (differences, ratios, rates).

Use the data to do one short calculation, such as a difference, ratio, or rate.

Core Idea

Use the data, then do the short math cleanly. ACT Science usually wants one simple calculation built from values you can read directly.

Understanding

These questions combine extraction with a small calculation. The math is usually a difference, ratio, average rate, or percent-style comparison, not a long algebra problem.

  • Read the needed values first.
  • Choose the right operation: difference, ratio, or change per unit.
  • Keep the units attached so you know whether the result should be colonies, mL per minute, or grams per liter.

Most misses are operation mistakes, not science mistakes.

Step by Step

  1. Write down the exact values named in the question.
  2. Decide whether the question asks for a difference, ratio, or rate.
  3. Perform the calculation with units included.
  4. Check whether the answer choice has the right magnitude and unit.

Misconceptions

  • Adding values when the question asks for change or difference.
  • Forgetting to divide by time when the question asks for a rate.
  • Reporting a raw number without the derived unit.
Question

Worked Example

Table 3 shows cell count in one culture: 12 cells at 0 min and 36 cells at 8 min. Based on Table 3, what was the average increase in cell count per minute over that interval?

Select an answer to see the explanation