Mathematics Achievement: Grade 5-6 School Mathematics
Thirty school-maths questions in thirty minutes across six strands, where a wrong answer means you worked it out wrongly, not thought about it wrongly.
44 topics · 165 questions
Each topic is a path, not a menu: work down it in order and every question builds on the one above. Click any of them to watch the answer draw itself.
Place Value and Reading Large Numbers
- How it worksHow does each step left along a number multiply a digit's worth by ten?
- Worked exampleFind the value of the digit 4 in 2,458,013 and name the place it sits in.
- Common mistakeWhy isn't the largest digit in a number always the digit worth the most?
The Four Operations with Whole Numbers
- How it worksHow does carrying a ten in addition move a whole bundle into the next column?
- How it worksWalk me through 6,042 minus 1,875 and show where every borrow comes from.
- Worked exampleFind 48 x 26 by splitting it into 48 x 20 plus 48 x 6.
- Common mistakeWhy doesn't a remainder mean you have done the division wrong?
Rounding and Making a Reasonable Estimate
- How it worksHow does the digit just to the right decide which way a number rounds?
- Worked exampleShow me 3,486 rounded to the nearest hundred and then to the nearest thousand.
- Common mistakeWhy isn't 449 rounded to the nearest hundred by rounding the 49 up first?
- Going furtherWhat happens to an estimated sum when every number gets rounded the same direction?
Order of Operations
- How it worksHow does an agreed order of operations stop one expression from having two meanings?
- Worked exampleFind the value of 20 - 2 x (3 + 4) and show each step in the order it must happen.
- Worked exampleFind the value of 6 + 18 / 3 - 2 x 4 by working left to right where the rules allow.
- Common mistakeWhy isn't multiplication always done before division when both show up?
Factors, Multiples, Greatest Common Factor and Least Common Multiple
- How it worksHow does listing factors in pairs make sure you never miss one?
- How it worksHow do two lists of multiples show you the first number both counts land on?
- Worked exampleFind the greatest common factor of 18 and 24, then the least common multiple of 4 and 6.
- Common mistakeWhy doesn't a greatest common factor ever come out bigger than the smaller number?
- Ties togetherHow does a least common multiple turn into the common denominator that fractions need?
Prime Numbers and Divisibility Rules
- How it worksHow does adding up a number's digits tell you whether 3 or 9 divides it?
- Worked exampleFind which of 2,001, 2,003, 2,005 and 2,007 divides by 9 with nothing left over.
- Common mistakeWhy isn't 1 counted as a prime when nothing except itself divides it?
- Going furtherWhat happens when you break 60 all the way down into a product of primes?
Exponents as Repeated Multiplication
- How it worksHow does a small raised number count how many times a base gets multiplied?
- Worked exampleFind the value of 3 to the fourth power and of 5 squared, then say which wins.
- Common mistakeWhy isn't 4 cubed the same thing as 4 times 3?
Equivalent Fractions and Simplest Form
- How it worksHow does re-dividing one shaded strip turn 1/2 into 4/8 without changing anything?
- Worked exampleFind the simplest form of 18/24 by pulling out the factor they share.
- Common mistakeWhy doesn't dividing only the top of a fraction leave its value alone?
- Going furtherWhat happens to a fraction's picture when top and bottom are both multiplied by 3?
Comparing and Ordering Fractions and Decimals
- How it worksHow does cutting two bars into matching pieces let you compare them at a glance?
- Worked exampleCompare 2/3, 5/8, 0.7 and 3/5 and put them in order from smallest to largest.
- Common mistakeWhy isn't 0.5 smaller than 0.45 even though 45 is bigger than 5?
- Going furtherWhat changes about comparing two fractions when their top numbers match instead?
Adding and Subtracting Fractions and Mixed Numbers
- How it worksHow does a common denominator re-cut two bars until their pieces finally match?
- Worked exampleFind 3/4 plus 5/6 and write the answer as a mixed number.
- Worked exampleFind 5 1/3 minus 2 3/4 by borrowing one whole and turning it into twelfths.
- Common mistakeWhy doesn't adding fractions mean adding the tops and adding the bottoms?
Multiplying and Dividing Fractions
- How it worksHow does taking 2/3 of 3/4 of a square show up as a shaded overlap?
- How it worksHow does flipping the second fraction turn a division into a multiplication?
- Worked exampleFind 2/3 times 9/10, and then find 3/4 divided by 1/2.
- Common mistakeWhy isn't dividing by 1/4 the same as dividing by 4?
Adding, Subtracting, Multiplying and Dividing Decimals
- How it worksHow does counting decimal places tell you where the point lands in a product?
- Worked exampleFind 4.7 times 0.6 and show exactly why the point ends up where it does.
- Worked exampleFind 12.6 divided by 0.4 by sliding both points the same number of places.
- Common mistakeWhy doesn't multiplying two decimals always give something bigger than both of them?
Converting Between Fractions, Decimals and Percents
- How it worksHow does a hundred-square turn any fraction into a percent you can see?
- Worked exampleShow me how 3/8 becomes a decimal and then becomes a percent.
- Worked exampleFind 0.35 written as a fraction in simplest form and also as a percent.
- Common mistakeWhy isn't 0.2 the same thing as 2 percent?
Finding a Percent of a Number
- How it worksHow does shading part of a hundred-square show what a percent of a number means?
- Worked exampleFind 25 percent of 64, and then find 15 percent of 80.
- Going furtherWhat happens to a 40 dollar price after a 25 percent cut and then a 10 percent cut?
- Common mistakeWhy doesn't a 20 percent rise followed by a 20 percent fall bring you back where you started?
Ratio and Simple Proportion
- How it worksHow does a ratio of 3 to 2 draw as two towers that grow together?
- Worked exampleFind how many boys sit in a class of 30 when boys to girls run 3 to 2.
- Common mistakeWhy isn't a ratio of 3 to 2 the same as saying 3 out of every 2 students are boys?
Number Patterns and What Comes Next
- How it worksHow do you test a guessed rule against every term before you trust it?
- Worked exampleFind the next two numbers in 3, 7, 11, 15 and name the rule that builds them.
- Worked exampleFind the missing number in 1, 4, 9, 16, blank, 36 and say what the pattern is doing.
- Going furtherWhat changes about a pattern when each term doubles instead of gaining a fixed amount?
Writing an Expression from Words
- How it worksHow do you turn each phrase of a sentence into one piece of an expression?
- Worked exampleBuild an expression for 3 tickets at t dollars each plus a 2 dollar booking fee.
- Common mistakeWhy isn't twice the sum of x and 4 written as 2x + 4?
Evaluating an Expression by Substitution
- How it worksHow does dropping one number into every copy of the letter finish the job?
- Worked exampleFind the value of 4n - 7 when n is 6, and then again when n is 2.
- Worked exampleFind the value of the expression 3(a + b) when a equals 5 and b equals 4.
- Common mistakeWhy isn't 2x equal to 25 when x is 5?
One-Step and Two-Step Equations
- How it worksHow does taking the same amount off both pans leave a balance still even?
- Worked exampleSolve 3x + 5 = 20 by undoing the plus 5 first and the times 3 second.
- Worked exampleSolve n / 4 = 9, and then solve 2n - 7 = 11.
- Common mistakeWhy isn't 3x + 5 = 20 solved by dividing only the 3x part by 3?
- Ties togetherHow does a two-step equation undo the very same two steps a number machine did?
Input-Output Tables and the Rule That Makes Them
- How it worksHow do you check a guessed rule on every row of a table at once?
- Worked exampleFind the rule sending 20 to 11, 16 to 9, 10 to 6 and 4 to 3, then find the input giving 15.
- Going furtherWhat happens to a table when its rule adds first and multiplies second instead?
Plotting a Point on a Coordinate Grid
- How it worksHow do you walk across first and up second to land on (3, 5)?
- Worked exampleGraph the points (3,5), (6,5), (8,2) and (2,2) and find which quadrilateral they make.
- Common mistakeWhy isn't (2, 5) the very same point as (5, 2)?
- Going furtherWhat happens to a plotted shape when 3 is added to every across coordinate?
Points, Lines, Rays and Naming Angles
- How it worksHow do you name an angle with three letters and keep the corner in the middle?
- Worked exampleDraw a right angle, an acute angle and an obtuse angle, then sort them by size.
- Common mistakeWhy doesn't drawing an angle's arms longer make the angle itself bigger?
Measuring and Classifying Angles
- How it worksHow does a protractor turn the opening between two rays into a number?
- Worked exampleFind the missing angle when two angles sitting on a straight line are 125 and x.
- Worked exampleFind the angle between a clock's hands at 3 o'clock and then at 4 o'clock.
- Going furtherWhat happens to the other three angles when two lines cross and one of them is 40 degrees?
Classifying Triangles and Quadrilaterals
- How it worksHow do sides and angles hand a triangle two different family names?
- How it worksHow does a family tree of quadrilaterals tuck squares inside rectangles?
- Worked exampleFind the name for a quadrilateral with exactly one pair of parallel sides.
- Common mistakeWhy isn't every rectangle a square when every square is a rectangle?
The Angle Sum of a Triangle
- How it worksHow does tearing off three corners and fitting them together prove the 180 degrees?
- Worked exampleFind the third angle of a triangle whose other two measure 47 and 68 degrees.
- Common mistakeWhy isn't a huge triangle's corner total any bigger than a tiny triangle's?
- Going furtherWhat happens to that total when you go from a triangle to a four sided shape?
Polygons, Circles and Their Parts
- How it worksHow do the radius, the diameter and the way around one circle depend on each other?
- How it worksHow does counting sides name a polygon from triangle all the way up to octagon?
- Worked exampleFind the diameter of a circle with a radius of 7 centimetres and compare the two.
- Common mistakeWhy isn't a shape with a curved side ever called a polygon?
Perimeter and Area of Rectangles and Triangles
- How it worksHow does walking all the way around a shape add up to its perimeter?
- How it worksHow do unit squares tiling the inside of a rectangle turn into length times width?
- Worked exampleFind the perimeter and the area of a rectangle 12 feet long and 8 feet wide.
- Worked exampleFind the area of a triangle with a base of 6 feet and a height of 8 feet.
- Common mistakeWhy isn't a triangle's area just base times height with no halving?
Area of Composite Shapes
- How it worksHow do you split an odd shape into pieces you already know how to measure?
- Worked exampleFind the area of a patio made from a 12 by 8 rectangle joined to a triangle 6 wide and 8 tall.
- Going furtherWhat happens when you get that same odd shape's area by subtracting rather than adding?
Symmetry, Congruence and Slides, Flips and Turns
- How it worksHow does sliding, flipping or turning a shape leave its size and shape untouched?
- Worked exampleFind how many lines of symmetry a square has and how many a long rectangle has.
- Common mistakeWhy doesn't turning a triangle upside down make it a different triangle?
- Going furtherWhat changes about a shape when you stretch it twice as wide but keep the height?
Solids and Their Faces, Edges and Vertices
- How it worksHow does unfolding a box into a flat net show every face at once?
- Worked exampleFind the faces, edges and vertices on a rectangular box and on a square pyramid.
- Common mistakeWhy isn't a cylinder called a prism when both have two matching ends?
Units and Tools for Length, Weight, Capacity, Time and Temperature
- How it worksHow do you pick the unit that makes a measurement easy to say out loud?
- Worked exampleFind the best unit and the right tool for weighing a letter, a person and a truck.
- Common mistakeWhy isn't the bigger number always the bigger amount when the units are different?
Converting Units Within One System
- How it worksHow does multiplying or dividing by the conversion number pick your direction?
- Worked exampleFind how many inches make up 4 feet 7 inches, using 12 inches in one foot.
- Worked exampleFind how many centimetres are in 2.5 metres when nobody hands you the conversion.
- Common mistakeWhy doesn't changing to a smaller unit mean you should divide?
Reading a Ruler, a Scale and a Thermometer
- How it worksHow do you work out what one small tick mark is worth on any scale?
- Worked exampleFind the length of a pencil ending three ticks past 5 when each inch splits into quarters.
- Going furtherWhat happens to your reading when the same dial counts by 2 rather than by 1?
Elapsed Time and Money Problems
- How it worksHow does jumping to the next whole hour make elapsed time easy to add up?
- Worked exampleFind how long a film runs if it starts at 2:45 and ends at 4:20.
- Worked exampleFind the change from a 20 dollar bill after 3 notebooks at 2.85 dollars each.
- Common mistakeWhy doesn't 1.5 hours mean one hour and fifty minutes?
Volume of a Rectangular Solid by Counting Cubes
- How it worksHow does one layer of cubes times the number of layers give the whole volume?
- Worked exampleFind the volume of a box 5 cubes long, 3 cubes wide and 4 cubes tall.
- Common mistakeWhy isn't volume measured in square units the way area is?
- Going furtherWhat happens to a box's volume when only its height gets doubled?
Mean, Median, Mode and Range
- How it worksHow do the mean, the middle value and the most common value answer different questions?
- Worked exampleFind the mean, median, mode and range of 4, 7, 7, 9 and 13.
- Common mistakeWhy isn't the median found before the numbers have been put in order?
- Going furtherWhat happens to both the mean and the median when one number jumps from 13 to 130?
Bar Graphs, Line Graphs and Pictographs
- How it worksHow does a pictograph key turn half a little symbol into a real number?
- Worked exampleFind the total when a pictograph shows 3 and a half book symbols worth 4 books each.
- Worked exampleBuild a bar graph from votes of 12, 8, 15 and 5 and find which bar ends up tallest.
- Going furtherWhat changes about a pictograph total when its key says 10 books per symbol instead of 4?
Circle Graphs and Tally Charts
- How it worksHow does a tally chart's bundle of five make a long count fast to read?
- Worked exampleFind how many of 60 students picked soccer when its slice fills a quarter of the circle.
- Common mistakeWhy doesn't a fat slice on one circle graph mean more people than a thin slice on another?
Probability of a Simple Event as a Fraction
- How it worksHow does counting the winning outcomes over all outcomes build a probability fraction?
- Worked exampleFind the probability of drawing the letter C from cards labelled A through K.
- Worked exampleFind the probability of rolling higher than 4 on one six sided number cube.
- Common mistakeWhy isn't a coin due to land heads after five tails in a row?
Certain, Likely, Unlikely and Impossible
- How it worksHow do you place an event on a line running from impossible to certain?
- Worked exampleFind where a chance of 7 out of 8 sits on a line from impossible to certain.
- Common mistakeWhy isn't an unlikely event the same thing as an impossible one?
Listing All the Possible Outcomes
- How it worksHow does a tree diagram grow one branch for every choice you could make?
- Worked exampleFind how many outfits come from 3 shirts and 4 pairs of shorts, then list them all.
- Worked exampleFind every outcome of tossing two coins and the chance of getting one of each.
- Going furtherWhat happens to the number of outcomes when a third coin joins the toss?
No Calculator: Mental Math and Checking Your Work
- How it worksHow does breaking a number into friendly parts let you multiply inside your head?
- Worked exampleFind 25 x 16 in your head by doubling and halving instead of writing it out.
- Going furtherWhat happens to your speed when you check an answer by estimating rather than redoing it?
Process Errors Hiding in the Answer Choices
- How it worksHow does each wrong choice match one exact mistake like a dropped decimal point?
- Worked exampleFind the wrong answers that appear when 15 x (8 + 17) is done three mistaken ways.
- Common mistakeWhy isn't an answer correct just because it turned up in the list of four?
- Going furtherWhat happens when you finish the problem before ever looking at the four choices?
Pacing 30 Questions in 30 Minutes
- How it worksHow does a section ordered easy to hard change which questions you skip?
- Worked exampleFind how much time is left for the last 10 questions when the first 20 took 22 minutes.
- Common mistakeWhy isn't skipping a hard question the same as giving up on it?
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