Overview
This lecture explains when and how to use answer choices strategically to quickly solve ACT Math questions, instead of doing lengthy algebraic calculations.
Using Answer Choices on the ACT Math Test
- You are allowed to use answer choices to help solve questions on the ACT Math Test.
- The main goal is to find the correct answer quickly, not to show step-by-step work.
- Sometimes plugging answer choices into the problem is faster than traditional methods, even if you know the math.
- Typically, start testing with choice C, the middle answer, to narrow down possibilities efficiently.
- If C is incorrect, determine if the answer should be higher or lower, then test one more choice.
- This strategy often requires testing only two answer choices rather than up to five if starting at A.
Example 1: Algebraic Substitution
- Sample question involves plugging values for n into an equation with answer choices: 1, 2, 4, 5, 6.
- Plugging in C (n=4) was too large, A (n=1) too small, so try B (n=2), which works.
- Using answer choices avoided complex algebra and was much quicker.
Example 2: Fractional Parts of a Whole
- Question asks for the total number of marbles given fractional parts and a fixed part.
- Plugging in C (72) gives a total that's too small, so try larger choices.
- D (84) matches the total when fractions and the specific number are summed.
- Setting up the equation would have taken longer than using answer choices.
When to Use This Method
- Use answer choices when algebraic setup and solving would take longer than trying answer options.
- Good candidates are questions involving complicated algebra, fractions, or multiple steps.
Key Terms & Definitions
- Plugging In — Trying answer choices in the given equation to see which fits.
- Starting with C — Testing the middle answer choice first, then adjusting up or down as needed.
- ACT Math Test — A standardized math test where efficiency and speed are prioritized over showing work.
Action Items / Next Steps
- Practice identifying ACT Math questions where plugging in answer choices is faster.
- Watch the next video on substituting in random numbers as an alternative strategy.