Pick. Watch. Again.
Step-by-step math
Choose a skill and we draw a question, then work through it one step at a time — with a sentence saying what just happened and why. There is nothing to answer and nothing is marked. When it finishes you can take another.
12 explained
Early Math
Counting, comparing, number bonds — the first ideas.Counting 4
Fractions 3
Comparing 1
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Comparing 1
Subtraction 1
93 explained
Arithmetic
The four operations, fractions, decimals, percent.Decimals 6
Fractions 2
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Fractions 12
- Adding like fractions2/6 + 4/6
- Adding mixed numbers3 1/7 + 3 1/2
- Adding unlike fractions3/8 + 2/6
- Comparing fractions4/8 ? 4/7
- Equivalent fractions1/4 = ?/8
- Fractions and decimals1/3 as a decimal
- Improper fractions to mixed numbers10/7 = ?
- Mixed numbers to improper fractions1 3/7 = ?
- Simplifying fractions3/9 = ?
- Subtracting fractions4/8 − 1/5
- Subtracting mixed numbers2 1/2 − 2 1/7
- Tenths and hundredths6/10 + 33/100
Addition 7
Mixed 4
Number patterns 3
Division 13
Remainders 1
Real life 3
Place value 8
- Estimating differences371 − 103
- Estimating products98 × 67
- Estimating sums and products161 + 708
- Expanded form105 in expanded form
- Identifying place value digitsWhich digit is in the ones of 647?
- Naming the placeWhich place is the 5 in, in 501?
- Rounding numbers867 to the nearest ten
- Whole-number place valueWhat is the 5 worth in 501?
Multiplication 16
- Missing factors4 × ? = 32
- Multiplication3 × 4
- Multiplication as scalingBigger or smaller?
- Multiplication by 108 × 10
- Multiplication by 1111 × 11
- Multiplication by 1211 × 12
- Multiplication by 28 × 2
- Multiplication by 48 × 4
- Multiplication by 58 × 5
- Multiplication by 68 × 6
- Multiplication by 78 × 7
- Multiplication by 88 × 8
- Multiplication by 98 × 9
- Multiplication facts3 × 4
- Times as many
- Times tables to 121 × 1
Subtraction 6
Percents 3
Ratios 4
42 explained
Word problems
Stories with a number in them — and which operation the story asks for.- Addition word problemsHow many acorns does Owl have in all?
- Age word problemsHow old is the footbridge?
- Averages word problemsWhat was the mean number of points?
- Consecutive number word problemsWhat is the smallest page number?
- Decimal word problemsFirst find the total, then the change.
- Division word problemsHow many hutches did Suki fill?
- Division word problems with remaindersHow many folders are left over?
- Equation word problemsWrite an equation using x for the unknown, then solve it.
Show 34 more word problems skills
- Fraction word problemsHow much juice does Ana need in all?
- Geometry word problemsWhat is the distance all the way around it, in meters?
- Median, mode, and range word problemsWhat is the mode?
- Mixed word problemsHow many bread rolls does Dev have in all?
- Mixture word problemsWhat is the price per kg of the blend?
- Multiplication word problemsHow many ration packs does Sato have in all?
- Probability word problemsWhat is the probability that it is NOT green? Write your answer in simplest form.
- Quadratic equation word problemsFind the two numbers.
- Ratio and proportion word problemsAt that rate, how long will it take to stamp 300 tickets?
- Speed, distance and time word problemsWhat is its speed in km per hour?
- Subtraction word problemsHow many pencils does Zoe have left?
- Systems of equations word problemsFind the price of one muffin and one peach.
- Three-step word problemsHow many strawberries does Ines have now?
- Two-step word problemsHow many tomatoes does Nadia have now?
- Value word problems (coins and notes)How many points is that in total?
- Word problems with extra informationHow many cupcakes does Marian have?
- Work and pipes word problemsHow long until the tank is full?
Algebra mistakes 9
- Algebraic fractionsCheck this line: (x² − 36) ÷ (x − 6) − x = 6. Which is correct?
- DistributingMia wrote 6(x + 4) + 5(x + 4) = 11x + 24. Which is correct?
- Dividing and signsNoor wrote 3(x + 7) − (x − 9) = 2x + 30. Which is correct?
- Exponent lawsOn Priya's paper: x³ · x³ ÷ x⁴ = x⁴. Which line should replace it?
- Logarithm lawsCheck this line: log(x²) + log(x⁵) = 7 log x. Which is correct?
- Multiplying two bracketsSpot the mistake: (x + 2)(x + 8) − x² = x² + 10x + 16. Which answer is right?
- Negative powersMia wrote x⁷ · x⁻³ = x²¹. Which is correct?
- Simplifying rootsCheck this line: √(96x²) + √(6x²) = 5x. Which is correct?
- Squaring a binomialAna wrote (x + 5)² − 25 = x² + 10x + 25. Which is correct?
Reasoning 8
- Always, sometimes, neverAn odd number times an even number is odd.
- Is it always true?The sum of four consecutive numbers is a multiple of 4.
- Number sequencesHere are the first four terms of a number sequence. 7 12 17 22
- Odd one outWhich number is the odd one out?
- Spot the errorPriya wrote 24 − 6 = 28. Write the correct answer.
- Statistical questionsIs it a statistical question?
- Symbol puzzles◆ + ◆ + ◆ = 12 and ◆ + ■ = 6. What is ■?
- The quadrilateral hierarchyEvery parallelogram is a rectangle.
20 explained
Real-Life Math
Clocks, money, calendars, measuring, converting.Real life 8
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Real life 5
44 explained
Pre-Algebra
Long division, factors, integers, solving for x.- 2-digit by 1-digit long division60 ÷ 6
- 2-digit by 1-digit multiplication22 × 7
- 2-digit by 2-digit multiplication53 × 41
- 3-digit by 1-digit multiplication704 × 5
- 4-digit by 1-digit long division6350 ÷ 5
- 4-digit by 1-digit multiplication8890 × 4
- 4-digit by 2-digit long division1680 ÷ 48
- Absolute value|−5| + |11|
Show 36 more pre-algebra skills
- Column addition & subtraction678 − 339
- Combining like terms2x + 4x + 20
- Distributive property3(4 + 4x)
- Equivalent expressionsWhich is the same as 3x + 8 + x?
- Evaluating expressions2x − 8, x = 5
- Greatest common factorGCF of 18 and 30
- Least common multipleLCM of 6 and 9
- List the factorsFactors of 16
- Long division837 ÷ 3
- Multi-digit multiplication158 × 33
- Multiplication and division inequalities−3x < −9
- One-step multiplication and division equationsx ÷ 6 = 3
- Order of operations5 × ( 18 − 18 )
- Percent change as one multiplierRead it in order, then say which way round
- Prime or compositeIs 24 prime?
- Solving equationsx − 7 = 20
- Solving inequalitiesx + 8 ≤ 20
- Two-step equations11x + 3 = 14
- Two-step inequalities−6x + 2 ≥ 38
- Variables on both sides10x + 13 = 12x + 3
- Which value makes it true?Try each value and see which one works
- Writing algebraic expressionsRead it in order, then say which way round
- Writing numerical expressionsRead it in order, then say which way round
Decimals 4
Ratios 3
Remainders 1
84 explained
Algebra 1
Expressions, straight lines, factoring, quadratics.- Absolute value equationsSolve |3x − 15| = 3
- Absolute value equations with coefficientsSolve |3x + 9| = 6
- Adding and subtracting polynomials(x + 9)(x + 1)
- Arithmetic and geometric sequences−8, −1, 6, 13, … — the 25th term
- Arithmetic sequence nth term−9, −8, −7, −6, … — the 24th term
- Common factor of three terms30x² + 18x + 18
- Common factor of two terms42x + 6
- Comparing rates from a tableA y = 10x, y dollars and x weeks B x: 2, 5, 8 y: 10, 25, 40
Show 76 more algebra 1 skills
- Comparing rates in wordsA y = 11x, y liters and x minutes B 65 liters in 5 minutes
- Composing functionsf(x) = −2x − 5, g(x) = −4x − 5; f(g(5))
- Difference of squares with coefficients100x² − 81
- Difference of two squaresx² − 900
- Discriminant with a leading coefficient8x² − 16x − 90 = 0
- Dividing in scientific notation(3 × 10²) ÷ (7.5 × 10⁻⁵)
- Evaluating exponential functionsEvaluate f(x) = 10 · 4ˣ at x = 2
- Evaluating functionsf(x) = −3x + 10; f(−6)
- Exponential functionsEvaluate f(x) = 2 · 8ˣ at x = 3
- Factor a difference of squaresx² − 225
- Factoring x² + bx + cx² + 12x + 11
- Factoring x² + bx − cx² + 8x − 345
- Factoring x² − bx + cx² − 29x + 138
- Finding the rate of changex: 4, 7, 10, 13 y: 109, 82, 55, 28
- Finding the x-interceptthe x-intercept of 3x + 5y = −15
- Finding the y-interceptthe y-intercept of 5x + y = 5
- Function notationf(x) = 2x + 11; f(−4)
- Geometric sequence nth term3, 6, 12, … — the 9th term
- How many real solutions?x² + 13x + 105 = 0
- Initial value from a tablex: 9, 14, 19, 24 y: 73, 108, 143, 178
- Line equation from two pointsWrite the equation of the line through (1, 4) and (2, 6)
- Multiply a sum by a difference(x + 10)(x − 10) − 10
- Multiplying and dividing in scientific notation(6 × 10⁸) ÷ (1.5 × 10⁻²)
- Multiplying in scientific notation(1.2 × 10⁻³) × (8 × 10²)
- Point-slope equation of a lineWrite the equation of the line with slope 2 through (3, 8)
- Rate of change from a tablex: 7, 12, 17, 22 y: 90, 65, 40, 15
- Rearranging formulasSolve V = ⅓Bh for B
- Solving (x − h)² = k by square rootsSolve (x + 5)² = 9
- Solving absolute value equationsSolve |x − 5| = 7
- Solving quadratics by square rootsSolve (x − 1)² = 25
- Solving x² + bx + c = 0(x + 9)(x + 8) = 0
- Solving x² = p by square rootsSolve 7x² = 28
- Taking out a common factor24x² + 120x + 168
- The discriminantx² + 35x + 44 = 0
- Transformations of a functionWhat happens to the graph?
- What the numbers in a rule meanWhat does the rule start at?
- Which rate is greater?A 42 dollars in 7 weeks B y = 11x, y dollars and x weeks
- Write the rule from a situationFind the start and the rate, then write the rule
- Writing linear equationsWrite the equation of the line through (1, −7) and (3, −15)
- x- and y-intercepts of a linethe x-intercept of x + 9y = −9
Exponents 11
- Cube roots∛1331
- Laws of exponents(4²)⁸
- Power of a power(12⁶)⁵
- Product rule for exponents3¹ × 3²
- Quotient rule for exponents4⁹ ÷ 4⁹
- Scientific notation3.8 × 10²
- Scientific notation: coefficient7300000
- Scientific notation: power of ten700000
- Scientific notation: small numbers3.6 × 10⁻³
- Square roots√289
- Square roots and cube roots√784
Pre algebra 21
- Estimating square roots√431
- Function from a tablex: 19, 5, 5, 8 y: 20, 3, 34, 56
- Function from ordered pairs(14, 34) (8, 5) (14, 6) (9, 12)
- How many solutions?2(−x + 6) = −2x + 12
- Is it a function?x: 0, 24, 7, 10 y: 31, 50, 7, 9
- Linear from a tablex: 0, 3, 6, 9 y: 5, 23, 77, 167
- Linear from an equationy = 10x² + 37
- Linear or nonlineary = x/5 + 20
- Number of solutions17x + 25 = 25 + 17x
- Rational or irrational0.1
- Rational or irrational numbers0.222…
- Rational or irrational roots√50
- Slope and y-intercepty = 8x
- Slope from an equationy = 11x
- Slope from two points(−1, 6) and (4, 6)
- Solutions after expanding3(3x + 1) = 9x + 3
- Square roots between integers√446
- Square roots to one decimal place√483
- Systems by elimination−6x + y = 23 12x − y = −47
- Systems by substitutiony = 4x − 1 −6x − y = 1
- Systems of equations6x + 12y = 18 2x − 12y = 22
Geometry 3
Graphs 1
11 explained
Algebra 2
Logs, radicals, complex numbers, rational expressions.- A line meeting a parabolaFind the x-values where y = x² + 2x − 23 meets y = x − 3
- Completing the squarex² − 6x + 24
- Complex numbers(3 + 3i) − (2 + 3i)
- Dividing polynomials(x³ + 8x² + 10x − 12) ÷ (x + 6)
- Laws of logarithms2 log₂ 3
- Logarithmslog₉ 1/81
- Multiplying and dividing rational expressionsx/(x − 7) × (x − 7)/(x − 4)
- Quadratics with complex solutionsSolve x² − 2x + 50 = 0
Show 3 more algebra 2 skills
90 explained
Geometry
Shapes, perimeter, area, angles, volume.- Alternate angles40° and x
- Angles around a pointAngles around a point: x, 125°, 140°
- Angles in a polygonAngles in a 10-sided shape
- Angles in a triangleThe third angle, given 35° and 40°
- Angles in an isosceles triangleIsosceles triangle angles
- Angles in parallel lines120° and x
- Angles on a line and around a pointAngles around a point: 120°, 95°, x
- Angles on a straight lineAngles on a line: x, 45°, 90°
Show 82 more geometry skills
- Arc lengthArc: 270° of a circle, radius 6
- Arc length and sector areaSector: 270° of a circle, radius 8
- Area by counting squaresArea of an L-shape by counting
- Area of a circleArea of a circle marked 8 cm
- Area of a circle from the diameterArea of a circle marked 16 cm
- Area of a parallelogramArea of a 6 by 17 parallelogram
- Area of a trapezoidArea of a trapezium, 3 and 4 by 4
- Area of a triangleArea of a 17 by 16 triangle
- Area of composite figuresArea of a 19 by 19 L-shape
- Area of irregular shapesArea of an L-shape by counting
- Area of triangles and quadrilateralsArea of a trapezium, 8 and 14 by 16
- Circumference from the diameterCircumference: circle marked 9 cm
- Circumference of a circleCircumference: circle marked 4 cm
- Circumscribed circle of a triangleThe circle through a 27-36-45 triangle's corners
- Classify triangles by anglesName this triangle
- Classify triangles by sidesName this triangle
- Classifying trianglesName this triangle
- Complementary and supplementary anglesAngles in a right angle, one is 27°
- Complementary anglesAngles in a right angle, one is 33°
- Corresponding angles40° and x
- CPCTC proofsWhich reason completes the proof?
- Density from area and volumePeople per square mile
- Dilations(2, 0) by scale factor ½
- Distance between two points(5, 7) to (9, 4)
- Distance formula(0, −5) to (4, −2)
- Exterior angle of a triangleThe exterior angle
- Faces, edges and verticespentagonal prism: how many edges?
- Find a side from the areaMissing side: area 126, one side 18
- Find a side from the perimeterMissing side: perimeter 50, one side 18
- Inscribed angle in a circleCenter angle 40°, find the angle on the circle
- Inscribed circle of a triangleThe circle inside a 27-36-45 triangle
- Lines of symmetryLines of symmetry: kite
- Midpoint formulaMidpoint of (-5, -5) and (1, 3)
- Midpoint of a segmentMidpoint of (0, 0) and (6, 8)
- Midsegment of a triangleThe midsegment
- Missing edge from the volumeMissing edge of a box, volume 175
- Missing side lengthMissing side: area 50, one side 10
- Naming 2D shapesName this shape
- Naming quadrilateralsName this shape
- Parallelogram proofsProve the property
- Perimeter of a parallelogramPerimeter of a 15 by 8 parallelogram
- Perimeter of a rectanglePerimeter of a 15 by 8 rectangle
- Perimeter of a trapezoidPerimeter of a 5-5-6-5 trapezoid
- Perimeter of a trianglePerimeter of a 13-13-20 triangle
- Perimeter of triangles and quadrilateralsPerimeter of a 19 by 8 parallelogram
- Pythagorean theoremRight triangle, 3 and 4
- Pythagorean theorem: find a legRight triangle, 34 and 16
- Pythagorean theorem: find the hypotenuseRight triangle, 16 and 30
- Reflections(5, 3) in the x-axis
- Rotational symmetryHow many times does it land on itself?
- Rotations(2, −2) 90° counterclockwise about O
- Sector areaSector: 45° of a circle, radius 6
- Similar figuresSimilar figures: 8 and 16
- Similar triangle proofsWhich reason completes the proof?
- Supplementary anglesAngles on a straight line, one is 25°
- Surface area and netsSurface area of a 7 × 10 × 13 box
- Surface area from a netSurface area of a 5 × 5 × 13 box
- Surface area of a rectangular prismSurface area of a 5 × 5 × 13 box
- Surface area of a sphereSurface area of a sphere, diameter 12 cm
- Transformations on a grid(0, −3) 90° counterclockwise about O
- Translations(−2, 0) 4 right and 4 up
- Triangle congruence proofsWhich reason completes the proof?
- Triangle congruence rulesWhich congruence rule?
- Triangle inequalityCan it be a triangle?
- Types of anglesName this angle
- Vertical angles
- Volume by counting unit cubesCounting unit cubes
- Volume of a coneA cone marked 3 cm, 2 cm tall
- Volume of a cylinderA cylinder marked 14 cm, 5 cm tall
- Volume of a rectangular prismVolume of a 9 × 7 × 9 stepped solid
- Volume of a sphereVolume of a sphere, diameter 12 cm
- Volume of composite solidsVolume of a 5 × 9 × 9 stepped solid
- Write a similarity proofProve △ADE ~ △ABC
- Write a triangle proofProve △PQR ≅ △PSR
Trigonometry 8
- Area of a triangle with sineFind the area
- Finding a missing angleFind the angle: opposite 13, adjacent 4
- Finding a missing sideFind the opposite, angle 65°
- Law of cosinesFind c by the law of cosines
- Law of sinesFind b by the law of sines
- Right-triangle trigonometryFind the angle: opposite 11, adjacent 6
- The six trig ratiosWrite tan A as a fraction
- Trigonometric ratiosWrite tan A as a fraction
41 explained
Data & Graphs
Tables, graphs, plots, averages, probability.Graphs 8
- And / or probabilityP(red or round) from red 4 round, 2 square · blue 3 round, 3 square
- Bar graphsOur favorite sport
- Box plot range and IQRScores on the spelling test (points)
- Box plotsScores on the spelling test (points)
- Circle graphsHow many more children walk to school than come by bus?
- Comparing two data setsHow many MADs apart are the two means?
- Complementary events2 red, 6 blue, 4 green — P(not red)
- Completing two-way tablesThe Small and Left number is missing
Show 33 more data & graphs skills
Graphs 33
- Conditional probabilityP(blue, given it is square) from red 5 round, 3 square · blue 2 round, 2 square
- Correlation and causationTry the cause both ways round
- Does the data fit the claim?Work out what the claim predicts, then compare
- Finding the meanMean of 39, 41, 46, 18, 46
- Finding the medianMedian of 20, 2, 26, 46, 46
- Four-quadrant coordinatesPoint C
- HistogramsStanding long jump (cm)
- Independent eventsAre the two events independent?
- Interquartile rangeIQR of 34, 48, 44, 21, 43, 20, 31
- Is this sample fair?Ask who could never have been asked
- Line plotsLength of our pencils (inches)
- Margin of errorOne over the square root of how many were asked
- Mean absolute deviationMAD of 7, 43, 33, 43, 4
- Mean, median, mode, and rangeMedian of 17, 41, 22, 17, 18
- Missing number from the meanMissing number for a mean of 12
- Picture graphsOur favorite sport
- Plotting pointsPoint A
- Points on a coordinate gridPoint A
- Probability3 red, 6 blue, 3 green — P(green)
- Reading box plotsScores on the spelling test (points)
- Relating two number patternsTwo rules, two patterns
- Relative frequencyOf the 25 Grade 7 students, what percent have a pet?
- Scatter plotsIs the pattern linear or nonlinear?
- Simple probability4 red, 4 blue, 4 green — P(blue)
- Stem-and-leaf plotsHow many values does the plot show?
- Survey, experiment or study?Ask first whether anything was assigned
- Tally chartsOur favorite sport
- The addition ruleWhat percent are one or the other?
- The counting principle3 frames, 2 wheels and 4 colors. How many different bikes can you make?
- The line of best fitIn y = 0.25x + 4, what does 4 mean?
- Three-stage counting principle9 mains, 3 sides and 7 drinks. How many different meals can you make?
- Two rules, two patterns
- Two-way tablesOf the 20 non-fiction borrowers, what percent returned it?
38 explained
Challenge
Puzzles you cannot start the moment you read them.- A diagonal through a boxCount the walls, then the ones crossed together
- A number from its remaindersClimb one list until it fits the others
- Cake numbersCount cuts, pairs and triples, do not just double
- Can it be done at all?A floor, and a route that reaches it
- Chickens & rabbitsAssume they are all the same, then fix it
- Color it firstColor the board, then count the two colors
- Counting diagonalsThe same count, minus the ones already joined
- Counting pairsCount the pairs without listing them
Show 30 more challenge skills
- Counting rectangles in a gridCount the rectangles without drawing them
- Counting triangles in a gridCount the triangles without drawing them
- Domino tilingsCount the tilings by the last column
- Fewest coinsThe obvious way to pay is not the fewest
- Integer trianglesOrder the sides, then keep only the ones that close up
- Lattice pathsCount the routes without drawing them
- Numbers too big to computeOnly the leftover moves the day
- One equation, two unknownsOne total, two unknowns, and only whole things
- Regions of a circleCount the chords and their crossings, do not just double
- Socks in the darkThe worst that can happen, then one more
- Sum and difference puzzlesTwo numbers from their total and their gap
- The fake coinA balance answers three ways, not two
- The gap between two squaresTwo squares apart, and the identity that makes it a list
- The hundred lockersOpen only where the count of divisors is odd
- The lazy catererCount cuts and their crossings, do not just double
- The number that cannot changeSomething does not change, whatever you pick
- The painted cubeWhere a cube sits decides how many faces are painted
- The smudged sumThe ten the ones column sends across
- The spider and the flyUnfold the box, then go straight
- The taking gameSometimes going first is the losing seat
- Things and the gaps between themThe things, or the gaps between them
- Three shares from one totalCount in parts, and take the extra off first
- Truth-tellers and liarsAnchor one islander, then follow the chain
- Two jugs and a tapMap every move to find the shortest route
- What the leftover meansThe division is not the answer
- What two facts settleSubtract the facts, not the prices
- Who am I? number puzzlesCross out everything the clues rule out
- Write your own questionThis one has more than one right answer