137 core topics
+ 16 prerequisite topics taught
as needed · approximately 36 hours of instruction
including spaced review
An adaptive diagnostic (up to
40 questions) places the student on the course's knowledge
graph — topics already known are credited, and instruction begins exactly
at the learning frontier. Every topic is taught with a worked-example
lesson and auto-graded practice; a topic is mastered at
75%+ and then maintained through spaced reviews on an
expanding schedule. A cumulative quiz follows every 6
lessons. Prerequisite gaps below the course are detected and taught rather
than skipped, so completion certifies the whole tower, not just the top.
| Adding & Subtracting Whole Numbers
[E] |
Multi-digit addition and subtraction. |
| Multiplication
[E] |
Multiplying whole numbers. |
| Division
[E] |
Dividing whole numbers. |
| Order of Operations
[M] |
Parentheses first, then multiplication/division, then addition/subtraction. |
| Negative Numbers: Adding & Subtracting
[M] |
Working with numbers below zero on the number line. |
| Negative Numbers: Multiplying & Dividing
[M] |
Sign rules for products and quotients. |
| Exponents
[M] |
Repeated multiplication in shorthand. |
| Square Roots
[M] |
Undoing a square. |
| Equivalent Fractions
[M] |
Different fractions can name the same amount. |
| Simplifying Fractions
[M] |
Reducing a fraction to lowest terms. |
| Adding Fractions (Like Denominators)
[M] |
Same-denominator addition. |
| Adding Fractions (Unlike Denominators)
[M] |
Rewrite over a common denominator first. |
| Multiplying Fractions
[M] |
Multiply straight across. |
| Dividing Fractions
[M] |
Multiply by the reciprocal. |
| Mixed Numbers & Improper Fractions
[M] |
Converting between forms. |
| GCF & LCM
[E] |
Greatest common factor and least common multiple. |
| Prime Factorization
[E] |
Every whole number is a unique product of primes. |
| Integer Operations
[E] |
Fluent four-operation arithmetic with negative numbers. |
| Absolute Value & Distance
[E] |
Absolute value is distance from zero. |
| Unit Rates
[E] |
Per-one comparisons: dollars per item, miles per hour. |
| Ratio Tables & Equivalent Ratios
[E] |
Scaling both parts of a ratio keeps it equivalent. |
| Solving Proportions
[E] |
Cross-multiply to find the missing value. |
| Percent Applications: Tax, Tip & Discount
[E] |
Real-world percents: discounts, tips, and tax. |
| Area: Triangles & Trapezoids
[E] |
Half of base times height — and its trapezoid cousin. |
| Area of Composite Figures
[E] |
Split odd shapes into rectangles and triangles. |
| Volume: Rectangular Prisms
[E] |
Length × width × height, fractional edges included. |
| Surface Area & Nets
[E] |
Unfold the box: surface area is the area of its net. |
| Mean, Median & Range
[E] |
Three ways to summarize a data set with one number. |
| Reading Data Displays
[E] |
Pulling answers out of dot plots, tables, and bar graphs. |
| Probability Basics
[E] |
Favorable outcomes over total outcomes. |
| Compound Probability
[E] |
Independent events multiply. |
| Constant of Proportionality
[M] |
The unit rate k in y = kx. |
| Graphing Proportional Relationships
[E] |
Straight line through the origin; slope = k. |
| Scale Drawings & Maps
[E] |
Scale is a ratio between drawing and reality. |
| Two-Step Inequalities
[M] |
Solve like an equation; flip when you multiply by a negative. |
| Angle Relationships
[E] |
Complementary (90°), supplementary (180°), vertical (equal). |
| Circumference & Area of Circles
[M] |
C = 2πr and A = πr². |
| Simple Interest & Percent Change
[M] |
I = P·r·t; balance = principal + interest. |
| Random Sampling & Inference
[E] |
Use a representative sample to estimate a whole population. |
| Comparing Two Populations
[E] |
Compare centers relative to spread. |
| Probability Models & Simulation
[E] |
Experimental probability from observed frequencies. |
| Opposites in Context
[E] |
Every number has a mirror twin on the other side of zero. |
| Absolute Value in Context
[E] |
Absolute value answers 'how far from zero?' — order answers 'which is greater?' |
| Comparing & Ordering Rational Numbers
[E] |
Smaller means farther left on the number line — even below zero. |
| Rational Numbers on the Number Line
[E] |
Fractions and decimals claim exact spots between the integers. |
| Plotting in All Four Quadrants
[E] |
Negative coordinates open up the other three quadrants. |
| Reflections Across the Axes
[E] |
Reflecting a point just flips the sign of one coordinate. |
| Distances on the Coordinate Plane
[M] |
Same x or same y: subtract and take the absolute value. |
| Rectangles on the Coordinate Plane
[M] |
Coordinates give the side lengths; perimeter and area follow. |
| Dividing Fractions: Word Problems
[M] |
'How many of this size fit?' is a division by a fraction. |
| Decimal Operations in Context
[E] |
Money problems are decimal arithmetic with two places, always. |
| Dividing Decimals in Context
[M] |
Slide both decimal points until the divisor is whole, then divide. |
| Percent of a Quantity: Parts & Wholes
[M] |
Percent problems run in three directions: find the part, the percent, or the whole. |
| Adding & Subtracting Signed Fractions
[M] |
Common denominators first, then the integer sign rules. |
| Adding & Subtracting Signed Decimals
[M] |
Balances, debts, and deposits: decimal arithmetic below zero. |
| Multiplying Signed Rationals
[M] |
Multiply the fractions, then apply the sign rules. |
| Dividing Signed Rationals
[M] |
Flip, multiply, and keep track of the sign. |
| Markup Then Discount
[H] |
Percent changes chain by multiplying, never by adding. |
| Discount, Tax & Tip Chains
[H] |
Work one percent step at a time — each acts on the previous result. |
| Proportional Word Problems
[M] |
Find the rate for one, then scale it to the amount asked. |
| Angle Equations: Complementary & Supplementary
[M] |
Complements sum to 90°, supplements to 180° — write the equation. |
| Angle Equations: Vertical Angles & Linear Pairs
[H] |
Vertical angles are equal; a linear pair sums to 180°. |
| Expanding with Rational Coefficients
[M] |
Distribute fractions and negatives to every term inside. |
| Factoring Linear Expressions
[M] |
Pull the GCF out front; distributing it back must restore the original. |
| Multi-Step Problems with Rationals
[H] |
Chain the operations one sentence at a time — fractions act on what's left. |
| Writing Addition & Subtraction Equations
[E] |
Turn a join-or-separate story into a one-step equation. |
| Writing Multiplication & Division Equations
[E] |
Equal-groups and fair-share stories become px = q or x ÷ p = q. |
| Solving Add & Subtract Equations in Context
[E] |
Undo one addition or subtraction to answer the story's question. |
| Solving Multiply & Divide Equations in Context
[E] |
Undo one multiplication or division to find the missing amount. |
| Is It a Solution?
[E] |
Substitute a value for the variable and see if both sides agree. |
| Money Equations
[M] |
One-step equations where the amounts are dollars and cents. |
| Evaluating Expressions in Context
[E] |
Substitute a number for the variable and follow the order of operations. |
| Dependent & Independent Variables
[E] |
Which quantity drives the relationship, and which one responds? |
| Using Two-Variable Equations
[E] |
Feed the independent variable into a rule to get the dependent one. |
| Writing Inequalities from Constraints
[E] |
Translate 'at least', 'more than', 'at most', 'fewer than' into symbols. |
| Graphing Inequalities on a Number Line
[E] |
Open or closed circle, shaded left or right — read and draw both ways. |
| Boundary Values of an Inequality
[E] |
Find the smallest or greatest whole number an inequality allows. |
| Area of a Circle
[E] |
Area is π times the radius squared. |
| Circumference of a Circle
[E] |
Circumference is π times the diameter. |
| Semicircles
[M] |
Half a circle: halve the area and the circumference. |
| Area of Composite Figures
[M] |
Break the figure into pieces, then add or subtract. |
| Scaling and Area
[M] |
Double the lengths, quadruple the area. |
| Volume of a Triangular Prism
[M] |
Triangle area times the prism's length. |
| Surface Area of a Prism
[M] |
Add the areas of all six rectangular faces. |
| Cross-Sections of Solids
[E] |
The shape revealed when a solid is sliced. |
| Angle Relationships as Equations
[M] |
Complementary sum to 90°, supplementary to 180°. |
| Working Backward from Area
[M] |
Undo πr² to recover the radius. |
| Constant of Proportionality from a Table
[M] |
Divide any y by its x — the ratio is the same every row, even when it is a fraction. |
| Constant of Proportionality from a Graph
[M] |
On a line through the origin, the constant of proportionality is the rise over the run to any point. |
| Constant of Proportionality from an Equation
[M] |
Solve the equation for y = kx; the coefficient of x is the constant, fractions and all. |
| Unit Rates as Complex Fractions
[M] |
A rate can be a fraction over a fraction — divide by multiplying by the reciprocal. |
| Complex-Fraction Rate Problems
[M] |
Real 'per one unit' rates when both quantities are fractions. |
| Redrawing at a New Scale
[M] |
Find the real length once, then convert it into any other drawing's scale. |
| Scale Drawings and Area
[M] |
Lengths scale by the factor; areas scale by the factor squared. |
| Successive Discounts
[M] |
Two discounts in a row multiply — they never simply add. |
| Commission
[M] |
Commission is a percent of sales; total pay may add a base salary. |
| Percent Error
[M] |
How far a measurement is off, as a percent of the true value. |
| Net Percent Change over Several Steps
[M] |
Chain percent changes by multiplying factors, then compare to the start. |
| Proportions with Unit Conversion
[M] |
Convert the units to match the rate before you scale. |
| Comparing Unit Rates (Best Buy)
[M] |
Reduce each deal to a price-per-one and compare those rates. |
| Expand, Then Combine Like Terms
[M] |
Distribute each factor, then gather the x-terms and the constants. |
| Collecting Like Terms
[M] |
Reorder freely, then add coefficients and add constants. |
| Factoring Out the GCF
[M] |
Pull the greatest common factor in front; the numbers left share no factor. |
| Identifying Equivalent Expressions
[M] |
Two expressions are equivalent when they agree for every value of x. |
| Writing Equivalent Expressions
[M] |
Describe a situation two ways, then simplify to a single equivalent form. |
| Two-Step Equation Word Problems
[M] |
Translate the story into ax + b = c, then undo the two operations. |
| Two-Step Equations with Money
[M] |
Subtract the flat fee, then divide by the count — answer to the cent. |
| Two-Step Equations: Geometry & Number Puzzles
[M] |
Perimeter formulas and number riddles both become ax + b = c. |
| Two-Step Inequality Word Problems
[M] |
“At most” and “at least” become ≤ and ≥; solve, then read off the count. |
| Graphing an Inequality's Solution
[M] |
Closed dot for ≤ or ≥, open dot for < or >; shade toward the solutions. |
| Rewriting to Reveal a Relationship
[M] |
A single combined expression can show a relationship the pieces hide. |
| Properties of Operations
[M] |
Name the property — distributive, commutative, associative, or identity. |
| Interpreting a Factored Form
[M] |
The factor pulled out front tells you what the value is a multiple of. |
| Sample Proportion as a Fraction
[E] |
The share of a random sample with a trait, written as a reduced fraction. |
| Estimating a Population Count
[M] |
Scale the sample proportion up to a whole population total. |
| A Sample Mean Estimates a Total
[M] |
Population total ≈ sample mean × population size. |
| Mean Absolute Deviation
[M] |
Average distance of the data from its mean — a measure of spread. |
| Comparing Two Means
[M] |
Compute each group's mean, then the gap between them. |
| Comparing Spread with MAD
[M] |
The data set with the larger MAD is the more variable one. |
| Difference as a Multiple of the MAD
[M] |
Measure the gap between two populations in MAD-sized steps. |
| Theoretical Probability of One Event
[M] |
Favorable outcomes over total equally likely outcomes, reduced. |
| Experimental Probability from Data
[M] |
Observed frequency of an outcome over the total number of trials. |
| Theoretical vs. Experimental
[M] |
Expected count = theoretical probability × trials; compare to what happened. |
| Compound Events by Organized List
[M] |
List every equally likely combined outcome, then count the favorable ones. |
| The Counting Principle
[M] |
Multiply the number of choices at each stage; multiply probabilities of independent events. |
| Estimating Probability from a Simulation
[M] |
A simulation's relative frequency estimates the true probability. |