The Common Core and other standards cover many algebraic topics before the first actual High
School Algebra course. In practice, not all students learn all these topics thoroughly before
starting High School, and this becomes a major impediment for them. We therefore include the
introductory lessons below in our algebra courses, but ideally students will work through them
in earlier grades, or in this separate preparatory course. This short course is thus designed to
be taken during the summer before High School, or concurrently with the first semester of High
School Algebra, if necessary.
These interactive lessons use dynamic graphing and guided discovery to strengthen and connect
symbolic and visual reasoning. They give the student a hands-on visual exposition of many
algebraic topics, reinforced by adaptive exercises and randomly generated tests. All
exercises and tests are checked and graded automatically. Hover the mouse over a link below to
see an example from that lesson, or click on a test link to see a concise
summary of a group of lessons. Relevant standards are listed
after each lesson’s exercises. We also provide
a course glossary.
Students should have scratch paper available, access to (software or hardware) numeric
calculators except during the Arithmetic Review chapter, and other students or a teacher to ask
for help when they are stuck. All students are encouraged to both give and receive
mathematical explanations with their peers. Please
send us your comments, questions and suggestions.
Arithmetic Review
Arithmetic on a Grid: Counting unit
squares. Sum, difference, product, quotient.
Two-Digit Addition: Two-digit numbers shown as
$a(10)+b$ on grid. Addition with regrouping, carrying.
Exercises: addition
Negative Numbers: Green squares have value
$+1$, pink squares have value $-1$. Sums and differences. Word problems involving debt.
Exercises: addition,
subtraction
Equations as Sentences: Solving equations
by trial and error, or by sliding a slider. Inverse problems as word problems.
Exercises: solving6.EE.5, A.CED.1
Grouping in Addition and Subtraction
Problems: Parentheses, associative law of addition, order of operations for addition
and subtraction. Simplifying expressions using the associativity of addition to regroup,
including for subtraction.
Exercises: evaluation,
simplifying6.EE.3, A.APR.1
Solving $x+b=c$: Adding a constant to both sides.
Exercises: solving6.EE.7, A.REI.1, A.REI.3
Slopes,
Rates of Change, and Similar Triangles: Calculating the slope of a line from any two
points on it. Derivation of the equation $y=mx$ or $y=mx+b$ from a line’s slope and
$y$-intercept.
Exercises:
computing slopes8.F.4, F.IF.6, F.LE.1b, F.LE.2