Quantitative Reasoning and Numerical Literacy
What is assessed
Arithmetic with fractions, decimals and percentages; ratio and proportion; the rule of three; averages (mean, median, mode) and range; reading tables and simple charts; and converting between units. Master percentage increase and decrease, successive percentage changes (which do not simply add), and the distinction between percentage points and percent. Learn to compute weighted averages, to reverse a percentage (finding the original value after a discount), and to handle ratios in sharing problems. In tables, check totals for consistency and read row and column headers carefully. Know that the mean is sensitive to outliers while the median is not.
Traps
A 20% increase followed by a 20% decrease does not return to the original value. A change from 4% to 6% is an increase of 2 percentage points but of 50 percent. Questions often mix up the base year, or ask for the average of a subset rather than the whole.
Worked example
A budget of 240,000 leva rises by 15%. The increase is 36,000 and the new budget is 276,000. If it then falls by 10%, the fall is 27,600, giving 248,400, not 240,000.
Rule of thumb
Write the base, the rate and the result explicitly before computing; never add percentages without checking the base.