Problem-Solving and Data Analysis · Mathématiques
Percentages au SAT
Percentages asks for percent change, a percent of a quantity, or the original value after a change. The reverse direction is the version most students get wrong.
- Section
- Mathématiques du SAT
- Domaine de contenu
- Problem-Solving and Data Analysis
- Part de la section
- 15%
- Questions notées
- Environ 6 par épreuve
Parmi les questions notées de cette section
Sur 40 questions notées dans la section
À quoi ressemblent les questions
A discount, a markup, a growth rate, or a described change, with a question about the new amount, the original amount, or the percent itself.
L'erreur qui coûte des points
Applying an increase and a decrease to the original number instead of the running total, and subtracting percentages that apply to different bases.
Comment la traiter
Turn each step into a multiplier: plus 20 percent is 1.2, minus 15 percent is 0.85, and chained changes multiply in order. To undo a change, divide by the multiplier instead of subtracting the percent.
Entraîne-toi sur Percentages
Dix questions sur cette compétence, sans chrono, avec l'explication après chaque réponse. Aucun compte requis ; connecte-toi et le même entraînement alimente aussi la précision par compétence que lit ton plan d'étude.
Questions sur Percentages
- Why is a 20 percent increase followed by a 20 percent decrease not back to the start?
- Because the second change is taken from the larger number. The two multipliers are 1.2 and 0.8, whose product is 0.96, so the result is 4 percent below where you began.
- How do you find the original amount after a percent change?
- Divide the final amount by the multiplier. If a price rose 25 percent to 80, divide 80 by 1.25 to get 64 rather than subtracting a quarter of 80.
- How many Percentages questions are on the SAT?
- College Board does not publish a count per question type, only per content domain. Problem-Solving and Data Analysis makes up about 15 percent of the Math section, which is roughly 6 of the 40 scored Math questions on a full form. Questions on this skill come out of that share.
Autres compétences en Problem-Solving and Data Analysis
- Ratios, rates, proportional relationships, and unitsThis skill is proportional reasoning and unit conversion: building a ratio from a description and converting between units without losing track of them.
- One-variable data: Distributions and measures of center and spreadOne-variable data asks you to read a distribution: mean, median, range, standard deviation, and how one added value shifts each of them.
- Two-variable data: Models and scatterplotsTwo-variable data asks you to read a line of best fit: what its slope means, how a prediction uses it, and how far the points sit from it.
- Probability and conditional probabilityProbability asks for the chance of an outcome from a table or a description, and the conditional version narrows the question to one group.