Percentages on the Digital SAT: the Desmos Method
A percent is a fraction with 100 underneath it, and "of" means multiply. So every percent question on this test is one multiplication typed onto one Desmos line — the only work is deciding what gets multiplied by what, and in which order.
Problem Solving & Data Analysis·65 practice problems in DesPrep
The Percentages lesson is part of DesPrep
It is one of the 17 full lessons inside the subscription — 7 sections that take percentages from first principles to the fastest Desmos route, with a worked example on every one:
- Percent means over one hundred. That is the whole definition.
- One line, one answer
- An increase is one multiplier, not two steps
- Read what they actually asked for
- A percent of a percent is a share of a share
- Two percents, two different bases: work inwards
- Up then down is not back where you started
Then 65 practice problems on this skill alone, solved inside a live Desmos calculator with step feedback and an expert replay on every one.
More Problem Solving & Data Analysis guides
- Scatterplots and ModelsGraph a line of best fit and read predictions straight off it, instead of substituting by hand.
- Ratios, Rates, Proportions and UnitsTurn a rate into a line and read any proportional value off it in seconds.
- Distributions, Center and SpreadMeans, medians and ranges computed in the Desmos list bar rather than on paper.
- ProbabilityTurn counts into a probability, reduced correctly every time, and keep track of which total the question restricts you to.