Course Updates for Pre-Algebra in July 2021
We are excited to share that we've made significant enhancements to our Pre-Algebra. One consequence of adding this new content is that it may impact learners’ Mastery percentages.
When we add new content and remove old content, Mastery percentages often change because the number of available skills changes. For example, if you mastered 90 out of 100 skills in a course, and we added 10 new skills, your mastery skill count would then be 90 out of 110. This change would change your Mastery percentage from 90% to 82%.
With this specific course update, we expect that Mastery percentages will change by a maximum of 61%. Most people will see a much smaller Mastery percentage change.
You can see exactly what content items we’ve added and removed below. Happy learning!
Content Added
Articles
Exercises
Combining like terms with negative coefficients & distribution |
Equations with variables on both sides: decimals & fractions |
Videos
Content Removed
Articles
Absolute value review |
Adding decimals |
Adding negative numbers review |
Associative property of multiplication review |
Classifying numbers review |
Common denominators review |
Commutative property of multiplication review |
Comparing fractions review |
Coordinate plane parts review |
Decimal place value review |
Decimals in expanded form review |
Decimals in written form review |
Decomposing fractions review |
Distributive property explained |
Distributive property review |
Dividing decimals |
Dividing fractions review |
Dividing negative numbers review |
Equivalent fractions review |
Factors and multiples review |
Graphing coordinates review |
Intro to absolute value |
Intro to negative numbers |
Mixed numbers and improper fractions review |
Multiplying decimals (no standard algorithm) |
Multiplying fractions review |
Multiplying negative numbers review |
Number opposites |
Number opposites review |
One-step equations review |
Ordering negative numbers |
Points on the coordinate plane |
Properties of addition |
Properties of multiplication |
Subtracting decimals |
Subtracting negative numbers review |
Whole number place value review |
Whole numbers in expanded form review |
Whole numbers in written form review |
Writing decimals as fractions review |
Writing fractions as decimals review |
Exercises
2-step expressions |
Absolute value to find distance |
Add and subtract fractions word problems |
Add and subtract fractions word problems (same denominator) |
Add and subtract mixed numbers (no regrouping) |
Add and subtract mixed numbers with unlike denominators (no regrouping) |
Add and subtract mixed numbers with unlike denominators (regrouping) |
Add fractions with common denominators |
Add fractions with unlike denominators |
Adding & subtracting decimals word problems |
Adding & subtracting negative numbers |
Adding decimals: hundredths |
Adding decimals: tenths |
Adding decimals: thousandths |
Adding negative numbers |
Approximating square roots |
Area & perimeter of rectangles word problems |
Associative property of multiplication |
Classify numbers: rational & irrational |
Common denominators |
Commutative property of multiplication |
Compare 2-digit numbers |
Compare and order absolute values |
Compare decimal place value |
Compare decimals (tenths and hundredths) |
Compare decimals through thousandths |
Compare fractions and mixed numbers |
Compare fractions on the number line |
Compare fractions using benchmark |
Compare fractions with different numerators and denominators |
Compare fractions with the same numerator or denominator |
Compare fractions word problems |
Comparing data displays |
Converting fractions to decimals |
Coordinate plane problems in all four quadrants |
Create bar graphs |
Create rectangles with a given area |
Cut shapes into equal parts |
Data set warm-up |
Decimals in expanded form |
Decimals in words |
Decimals in written and expanded form |
Decimals on the number line: hundredths |
Decimals on the number line: tenths |
Decimals on the number line: thousandths |
Decompose fractions |
Decompose fractions visually |
Distance between points: vertical or horizontal |
Distributive property |
Divide fractions and whole numbers word problems |
Divide mixed numbers |
Dividing decimals 1 |
Dividing decimals 2 |
Dividing decimals: hundredths |
Dividing decimals: thousandths |
Dividing fractions |
Dividing fractions word problems |
Dividing negative numbers |
Dividing unit fractions by whole numbers |
Dividing whole numbers by unit fractions |
Dividing whole numbers like 56÷35 to get a decimal |
Divisibility tests |
Equivalent fractions |
Equivalent fractions |
Equivalent fractions (fraction models) |
Equivalent fractions (number lines) |
Factor with the distributive property (no variables) |
Find a missing side length when given perimeter |
Find area by counting unit squares |
Find area with partial unit squares |
Find perimeter by counting units |
Find perimeter when given side lengths |
Finding absolute values |
Fraction multiplication as scaling |
Fractions as division |
Fractions greater than 1 on the number line |
Fractions in contexts |
Fractions on the number line |
GCF & LCM word problems |
Greatest common factor |
Identify points on a line |
Identify value of a digit |
Interpreting negative numbers |
Least common multiple |
Multiply fractions and whole numbers |
Multiply fractions and whole numbers on the number line |
Multiply fractions and whole numbers with fraction models |
Multiply fractions word problems |
Multiply mixed numbers |
Multiply mixed numbers and whole numbers |
Multiplying decimals like 0.847x3.54 (standard algorithm) |
Multiplying decimals like 2.45x3.6 (standard algorithm) |
Multiplying decimals like 4x0.6 (standard algorithm) |
Multiplying fractions |
Multiplying fractions with visuals |
Multiplying negative numbers |
Negative numbers on the number line |
Number opposites |
Order decimals |
Order decimals and fractions in different forms |
Order fractions |
Ordering negative numbers |
Place value tables |
Place value when multiplying and dividing by 10 |
Points on the coordinate plane |
Powers of products & quotients (structured practice) |
Prime factorization |
Properties of exponents challenge (integer exponents) |
Quadrants on the coordinate plane |
Rate problems 2 |
Read bar graphs (2-step problems) |
Read histograms |
Read picture graphs (multi-step problems) |
Reading dot plots & frequency tables |
Reading stem and leaf plots |
Recognize fractions |
Reflecting points in the coordinate plane |
Regroup whole numbers |
Relate decimals and fractions in words |
Relate number lines to fraction bars |
Represent rectangle measurements |
Represent the commutative property of multiplication |
Rewriting decimals as fractions challenge |
Round decimals |
Round decimals challenge |
Round decimals using a number line |
Round whole numbers |
Signs of expressions |
Simplify fractions |
Simplify square roots |
Subtract fractions with common denominators |
Subtracting decimals: hundredths |
Subtracting decimals: tenths |
Subtracting decimals: thousandths |
Subtracting fractions with unlike denominators |
Subtracting negative numbers |
Transition from unit squares to area formula |
Understand associative property of multiplication |
Understand multiplying by a multiple of 10, 100, and 1000 |
Understand numerators and denominators |
Understand subtraction as adding the opposite |
Understand the commutative property of multiplication |
Unit fractions on the number line |
Use associative property to multiply 2-digit numbers by 1-digit |
Using units to solve problems |
Visualize distributive property |
Visually add and subtract fractions |
Volume of rectangular prisms |
Volume of rectangular prisms with unit cubes |
Volume word problems |
Write common fractions as decimals |
Write decimals and fractions greater than 1 shown on grids |
Write decimals and fractions shown on grids |
Write decimals and fractions shown on number lines |
Write decimals as fractions |
Write fractions as decimals (denominators of 10 & 100) |
Write mixed numbers and improper fractions |
Write whole numbers in expanded form |
Writing numerical inequalities |
Videos
1 and -1 to different powers |
2-step estimation word problems |
Absolute value as distance between numbers |
Absolute value examples |
Adding & subtracting decimals word problem |
Adding & subtracting negative numbers |
Adding decimals with ones, tenths and hundredths |
Adding decimals word problem |
Adding decimals: 0.822+5.65 |
Adding decimals: 9.087+15.31 |
Adding fractions with like denominators |
Adding fractions with unlike denominators |
Adding fractions word problem: paint |
Adding mixed numbers with like denominators |
Adding mixed numbers with regrouping |
Adding mixed numbers: 19 3/18 + 18 2/3 |
Adding negative numbers example |
Adding numbers with different signs |
Adding three decimals |
Adding whole numbers by their place values |
Approximating square roots to hundredths |
Area & perimeter word problem: dog pen |
Area & perimeter word problem: table |
Associative law of addition |
Associative law of multiplication |
Associative property of multiplication |
Classifying numbers: rational & irrational |
Common denominators: 1/4 and 5/6 |
Common denominators: 3/5 and 7/2 |
Common divisibility examples |
Commutative law of addition |
Commutative law of multiplication |
Commutative property of multiplication |
Comparing absolute values |
Comparing and ordering fractions |
Comparing decimals 2 |
Comparing decimals 3 |
Comparing decimals: 156.378 and 156.348 |
Comparing decimals: 9.97 and 9.798 |
Comparing dot plots, histograms, and box plots |
Comparing fractions |
Comparing fractions 2 (unlike denominators) |
Comparing fractions with > and < symbols |
Comparing fractions with like numerators and denominators |
Comparing improper fractions and mixed numbers |
Comparing place values |
Comparing whole number place values |
Converting decimals to fractions 2 (ex 1) |
Converting decimals to fractions 2 (ex 2) |
Coordinate plane word problem examples |
Counting unit squares to find area formula |
Creating a bar graph |
Creating a fraction through division |
Creating rectangles with a given area 1 |
Creating rectangles with a given area 2 |
Cube root of a non-perfect cube |
Cutting shapes into equal parts |
Decimal place value |
Decimals as words |
Decomposing a fraction visually |
Decomposing a mixed number |
Developing strategies for multiplying decimals |
Distributive property exercise examples |
Distributive property when multiplying |
Divide whole numbers with decimal quotients: 5÷2 |
Divide whole numbers with decimal quotients: 78÷12 |
Dividing by a multi-digit decimal |
Dividing decimals completely |
Dividing decimals with hundredths |
Dividing fractions by whole numbers: studying |
Dividing fractions: 2/5 ÷ 7/3 |
Dividing fractions: 3/5 ÷ 1/2 |
Dividing positive and negative numbers |
Dividing whole numbers & fractions: t-shirts |
Dividing whole numbers to get a decimal |
Divisibility tests for 2, 3, 4, 5, 6, 9, 10 |
Division strategies for decimal quotients |
Equivalent fraction and whole number multiplication problems |
Equivalent fraction models |
Equivalent fractions |
Exponentiation warmup |
Exponents and powers of 10 patterns |
Expressing decimals in multiple forms |
Finding average speed or rate |
Finding common denominators |
Finding missing side length when given perimeter |
Finding perimeter when a side length is missing |
Finding place value |
Finding the point not graphed |
Fraction to decimal: 11/25 |
Fraction word problem: lizard |
Fraction word problem: piano |
Fractions on a number line |
Fractions on number line widget |
Frequency tables & dot plots |
GCF & LCM word problems |
Graphing hundredths from 0 to 0.1 |
Graphing tenths from 0 to 1 |
Greater than and less than symbols |
Greatest common factor examples |
Greatest common factor explained |
Growing by a percentage |
Histograms |
Identifying hundredths on a number line |
Identifying numerators and denominators |
Identifying percent amount and base |
Identifying tenths on a number line |
Identifying unit fractions word problem |
Identity property of 0 |
Identity property of 1 |
Inequality word problem: one variable |
Inequality word problems |
Interpreting bar graphs: alligators |
Intro to area and unit squares |
Intro to fractions |
Intro to multiplying 2 fractions |
Intro to multiplying decimals |
Intro to negative numbers |
Intro to rational & irrational numbers |
Introduction to adding decimals: tenths |
Introduction to scientific notation |
Inverse property of addition |
Inverse property of multiplication |
Least common multiple |
Least common multiple of three numbers |
Least common multiple: repeating factors |
Long division with decimals |
Measuring area with partial unit squares |
Measuring rectangles with different unit squares |
Measuring volume as area times length |
Measuring volume with unit cubes |
Misleading line graphs |
More advanced subtraction strategies with hundredths |
More on equivalent fractions |
Multi-digit division strategies for decimals |
Multiple rates word problem |
Multiple units word problem: road trip |
Multiplication as scaling with fractions |
Multiplying 2 fractions: 5/6 x 2/3 |
Multiplying 2 fractions: fraction model |
Multiplying 2 fractions: number line |
Multiplying challenging decimals |
Multiplying decimals using estimation |
Multiplying decimals: place value |
Multiplying fractions and whole numbers visually |
Multiplying fractions word problem: bike |
Multiplying fractions word problem: laundry |
Multiplying fractions word problem: muffins |
Multiplying in scientific notation example |
Multiplying mixed numbers |
Multiplying positive & negative numbers |
Negative symbol as opposite |
Number opposites |
Order of operations (2-step expressions) |
Ordering decimals 1 |
Ordering decimals 2 |
Ordering fractions |
Ordering negative numbers |
Ordering numeric expressions |
Orders of magnitude exercise example 1 |
Orders of magnitude exercise example 2 |
Percent word problem: 78 is 15% of what number? |
Percent word problem: penguins |
Perimeter of a shape |
Perimeter: introduction |
Place value tables |
Place value when multiplying and dividing by 10 |
Place value with decimals |
Placing absolute values on the number line |
Plotting a point (ordered pair) |
Plotting decimal numbers on a number line |
Points and quadrants example |
Points on the coordinate plane examples |
Prime factorization |
Prime factorization exercise |
Properties and patterns for multiplication |
Properties of multiplication |
Quadrants of the coordinate plane |
Reading bar graphs |
Reading pictographs |
Reading pie graphs (circle graphs) |
Reading stem and leaf plots |
Recognize fractions |
Recognizing divisibility |
Recognizing fractions greater than 1 |
Reflecting points in the coordinate plane |
Regrouping numbers into various place values |
Regrouping whole number place values |
Regrouping whole numbers: 430 |
Regrouping whole numbers: 675 |
Regrouping whole numbers: 76,830 |
Relating decimals and fractions in words |
Representing data |
Rewriting decimals as fractions: 0.15 |
Rewriting decimals as fractions: 0.36 |
Rewriting decimals as fractions: 0.8 |
Rounding decimals on the number line |
Rounding to the nearest 10 on the number line |
Rounding to the nearest 100 on the number line |
Rounding whole numbers to nearest hundred |
Rounding whole numbers to nearest ten |
Rounding whole numbers to nearest thousand |
Scientific notation examples |
Setting up 2-step word problems |
Simplifying a cube root |
Simplifying square roots |
Solving ratio problems with graph |
Speed translation |
Stem-and-leaf plots |
Strategies for dividing by tenths |
Strategies for subtracting more complex decimals with tenths |
Subtracting a negative = adding a positive |
Subtracting decimals: 39.1 - 0.794 |
Subtracting decimals: 9.005 - 3.6 |
Subtracting fractions with like denominators |
Subtracting fractions with unlike denominators |
Subtracting fractions word problem: tomatoes |
Subtracting mixed numbers with like denominators |
Subtracting mixed numbers with regrouping (unlike denominators) |
Subtracting mixed numbers: 7 6/9 - 3 2/5 |
The 0 & 1st power |
The why of the 3 divisibility rule |
The why of the 9 divisibility rule |
Thousandths on the number line |
Transitioning from unit squares to area formula |
Understanding decimal multiplication |
Understanding division of fractions |
Understanding fractions as division |
Understanding place value |
Understanding square roots |
Using associative property to simplify multiplication |
Visual understanding of regrouping decimals |
Visualizing equivalent fractions |
Visually adding fractions: 5/6+1/4 |
Visually subtracting fractions: 3/4-5/8 |
Volume intro |
Volume of a rectangular prism |
Volume word problem: water tank |
Why a negative times a negative is a positive |
Why a negative times a negative makes sense |
Worked example: Converting a fraction (7/8) to a decimal |
Worked example: Rounding decimals to nearest tenth |
Write decimal in expanded form |
Writing a number as a fraction and decimal |
Writing a number in expanded form |
Writing a number in standard form |
Writing decimal numbers shown in grids |
Writing decimals and fractions greater than 1 shown on grids |
Writing decimals and fractions shown on number lines |
Writing improper fractions as mixed numbers |
Writing mixed numbers as improper fractions |
Writing numbers in words and standard form |