Comprehensive reviewer for the National Achievement Test (NAT) Grade 10 — Mathematics. It covers the most-tested skills with worked examples and test strategy.
Number Sense & Operations
Master the four operations on integers, fractions, and decimals, plus the order of operations.
| Operation | Rule | Example |
|---|---|---|
| (−)(−) | positive | (−4)(−2)=8 |
| Add fractions | common denominator first | 1/2+1/3=5/6 |
| Percent | part = rate × base | 20% of 50 = 10 |
Do operations inside parentheses and exponents BEFORE multiplying or adding. Left-to-right for same-level operations.
Algebra
Translate words into equations and solve linear and quadratic equations.
Quadratic: x = [−b ± √(b²−4ac)] ÷ 2a
Keywords: "is" = (=), "of" = (×), "more than" = (+), "less than" = (−). Build the equation, then isolate the variable.
Geometry & Measurement
| Figure | Perimeter | Area |
|---|---|---|
| Rectangle | 2(L+W) | L×W |
| Triangle | a+b+c | ½bh |
| Circle | C=πd | πr² |
Volume of box = L×W×H
Perimeter is the distance AROUND (1D, units like cm); area is the space INSIDE (2D, units like cm²). Do not mix them.
Statistics & Probability
| Measure | How to find |
|---|---|
| Mean | sum ÷ count |
| Median | middle of ordered data |
| Mode | most frequent |
Permutation nPr (order matters); Combination nCr (order not)
Always ARRANGE data before finding the median. Probability is always between 0 and 1.
Sequences & Patterns
| Sequence | Rule | nth term |
|---|---|---|
| Arithmetic | add d | aₙ=a₁+(n−1)d |
| Geometric | multiply r | aₙ=a₁·r^(n−1) |
Identify the pattern first: are you ADDING a constant (arithmetic) or MULTIPLYING (geometric)?
Trigonometry
Label the sides relative to the angle (opposite, adjacent, hypotenuse), then pick the ratio using the two sides involved.
Worked Examples
1. A shirt costs ₱500 with a 20% discount. Final price?
2. Find the mean of 12, 15, 18, 15.
3. Solve x² − 7x + 12 = 0.
Test-Taking Strategy
Read carefully and underline what is ASKED. Eliminate impossible options. Substitute answer choices back when stuck. Do easy items first; never leave blanks — there is no wrong-answer penalty.
Watch units and "EXCEPT/NOT" questions. Re-check whether the question wants the value, the difference, or the percentage.