OSAT Middle Level/Intermediate Mathematics (225) study materials
OSAT Middle Level/Intermediate Mathematics (225) study resources

OSAT Middle Level/Intermediate Mathematics (225) study plan

OSAT Middle Level/Intermediate Mathematics (225) · Give each week a clear focus.

8 weeks · About 7 hours per week

Week 1

Number Sense and Operations

  • Compute fluently with rational numbers in all four operations, including signed fractions, decimals, and mixed numbers, without a calculator.

  • Convert among fractions, decimals, and percents and order a mixed set of ten values from least to greatest.

  • Apply order of operations and properties of exponents (product, quotient, power, zero, negative) to simplify 20 numeric expressions.

  • Classify numbers as rational or irrational and place square roots of non-perfect squares between consecutive integers.

Your checkpoint

A timed 25-question number sense quiz scored at 88% or higher, with every missed item rewritten and re-solved correctly.

Week 2

Number Sense and Operations

  • Solve multi-step percent problems: percent change, tax, discount, markup, simple interest, and percent error.

  • Compute with ratios, rates, unit rates, and proportional reasoning, including scale factors and similar-figure side lengths.

  • Solve problems involving scientific notation, including multiplication and division with exponent rules.

  • Apply divisibility rules, prime factorization, GCF, and LCM to simplify and combine fractions and radicals.

Your checkpoint

A one-page error log of 15 mixed number-sense problems, each showing the correct method and the specific rule that was initially misapplied.

Week 3

Algebra and Functions

  • Solve linear equations and inequalities in one variable, including those with fractions, absolute value, and variables on both sides.

  • Graph linear equations and inequalities on the coordinate plane and interpret slope as a rate of change.

  • Write equations of lines given two points, a point and a slope, or a parallel/perpendicular condition.

  • Solve systems of two linear equations by substitution, elimination, and graphing, and classify as consistent, inconsistent, or dependent.

Your checkpoint

A 20-problem linear-functions set scored at 85% or higher, including at least four word problems translated from context to equation.

Week 4

Algebra and Functions

  • Add, subtract, multiply, and divide polynomial expressions, including binomial expansion and factoring of trinomials.

  • Factor completely using GCF, difference of squares, and trinomial methods, and use factoring to solve quadratic equations.

  • Apply the quadratic formula and discriminant to determine the number and type of solutions.

  • Evaluate, compose, and find inverses of functions, and identify domain and range from equations and graphs.

Your checkpoint

A two-page summary sheet of factoring and quadratic techniques with one worked example each, plus a 15-question self-test at 80% or higher.

Week 5

Geometry and Measurement

  • Compute perimeter, area, surface area, and volume for polygons, circles, prisms, cylinders, pyramids, cones, and spheres.

  • Apply the Pythagorean theorem and distance formula to find lengths and verify right triangles.

  • Use angle relationships (parallel lines and transversals, triangle angle sum, exterior angles, inscribed angles) to find missing measures.

  • Perform unit conversions within and across measurement systems and compute with significant precision appropriate to the problem.

Your checkpoint

A formula reference card plus a 20-problem measurement set scored at 85% or higher, with units labeled on every answer.

Week 6

Geometry and Measurement

  • Transform figures using translations, rotations, reflections, and dilations on the coordinate plane and describe the effect on coordinates.

  • Prove and apply congruence and similarity criteria for triangles, including ratio of areas and volumes under scaling.

  • Solve coordinate-geometry problems involving slope, midpoint, and parallel/perpendicular lines.

  • Analyze three-dimensional solids from nets and cross-sections and compute composite-figure area and volume.

Your checkpoint

A set of six labeled coordinate-plane sketches demonstrating each transformation and a written similarity proof, self-checked against a rubric you write.

Week 7

Statistics, Probability, and Data Analysis

  • Compute and interpret mean, median, mode, range, quartiles, and interquartile range, and identify outliers.

  • Read and construct displays: histograms, box plots, scatter plots, and two-way tables, and describe association and trend.

  • Compute probabilities for simple, compound, and conditional events, including independent versus dependent events and the complement rule.

  • Distinguish correlation from causation and evaluate sampling methods and sources of bias.

Your checkpoint

A one-page statistical report analyzing a dataset you choose, including a box plot, a scatter plot with a described trend, and a probability calculation with justification.

Week 8

Number Sense and Operations & Algebra and Functions & Geometry and Measurement & Statistics, Probability, and Data Analysis

  • Complete two full-length timed practice tests under exam conditions and record per-domain accuracy.

  • Re-teach the two weakest domains using targeted drills until each reaches 85% accuracy.

  • Review all error logs and formula cards, re-solving every previously missed problem without notes.

  • Practice pacing and calculator-free arithmetic strategies to finish each section with five minutes remaining.

Your checkpoint

A final score report across both practice tests showing per-domain accuracy, with every domain at 80% or higher and a written list of remaining weak spots.

Milestones

Week 2: Score 85% or higher on a 20-question cumulative number-sense test taken without a calculator.

Week 4: Score 80% or higher on a mixed algebra test covering linear, quadratic, and function items, and explain two solution methods aloud.

Week 6: Score 80% or higher on a geometry and measurement test, with correct units on at least 90% of items.

Week 8: Average 80% or higher across both full-length practice tests with no single domain below 75%.