Tag
Sums
Adding, taking away, sharing, and times tables — 43 tiny stories across 4 shelves.
Math
Number ideas with toys — 39 stories.
All math →Putting together
What Does Adding Do?
Adding only gathers — nothing is created. The order makes no difference, which halves what anyone has to memorise, and hard sums split into friendly steps.
Let’s go →A recipe with no judgement
What Makes Something an Algorithm?
An algorithm is a list of steps precise enough to need no judgement: every decision definite, every step doable, and the whole thing finishes.
Let’s go →Counting squares, quickly
Why Do We Multiply to Find Area?
Area counts the squares covering a shape, and multiplying rows by columns is a fast way of counting them. Double both sides and you get four times as many.
Let’s go →Counting without counting
Why Are Rows and Columns Useful?
Lay things out in rows and columns and counting one by one becomes multiplying. The grid also shows why the order of the two numbers cannot matter.
Let’s go →Levelling everyone off
What Does an Average Actually Tell You?
An average is what everyone would get if the total were shared out evenly. It is a fact about a group rather than about any one member of it.
Let’s go →A 50.7 per cent chance
In a Room of Twenty-Three, Two People Share a Birthday
With 23 people the odds of a shared birthday pass one half, because 23 people make 253 pairs — and it is the pairs, not the people, that get the chances.
Let’s go →The small things add up first
Why Does the Money Run Out Before the Month?
Budgets fail on the small, frequent spending rather than the big purchases you remember — so the number that matters is price times how often.
Let’s go →More orders than atoms nearby
Has Anyone Ever Had This Hand Before?
Adding the numbers one to fifty-two gives a few thousand; multiplying them fills sixty-eight digits. It takes seven riffles to reach that properly.
Let’s go →Counting up, not taking away
How Do You Work Out Your Change?
Your change is not a distance but a sum of hops counted forwards from the price. That is why the small coins come out first — the order the hops came in.
Let’s go →Interest on the interest
Why Does Saved Money Grow Faster Each Year?
Interest is added to your money, and next year you earn interest on that too. The curve accelerates — and it works exactly as hard against you on debt.
Let’s go →One thing, one word
How Does Counting Work?
Counting has three rules: one word per object, always the same order, and the last word is the answer. Young children reliably miss the third one.
Let’s go →Count a little, multiply a lot
How Do You Count a Huge Crowd?
Any count taking an hour is counting a different crowd by the end, so one square is counted and the rest is measured. All the error lives in that square.
Let’s go →More ways to get there
Why Is Seven the Commonest Roll?
Two dice do not make every total equally likely. Six different pairs add up to seven, while two and twelve have exactly one route each.
Let’s go →Taking a slice off the top
How Do Shops Work Out a Sale Price?
A discount is a percentage of the old price, so the same thirty per cent off saves wildly different amounts — and two discounts never simply add up.
Let’s go →Fair shares
How Does Division Work?
Division takes one pile and shares it into equal groups, and the answer it hands back is the size of a single group rather than the number of groups.
Let’s go →Two of the same
What Does Doubling Mean?
Doubling adds a copy rather than a fixed amount, so it grows far faster than anyone expects: ten doublings of 1 reach 1,024, and thirty pass a billion.
Let’s go →Balance, not 'the answer'
What Does the Equals Sign Really Mean?
Equals does not mean an answer comes next. It means both sides are worth the same, which is why 7 = 4 + 3 is perfectly correct written that way round.
Let’s go →Close enough on purpose
What Is Estimating?
An estimate trades precision for speed, and it is often the better answer — as well as the check that catches an exact calculation gone badly wrong.
Let’s go →Comparing
Which Number Is Bigger?
A number is bigger if you reach it later while counting — further right on the number line, whatever the number happens to look like.
Let’s go →Small steps that stop being small
Why Does Doubling Get Out of Hand?
Ten doublings multiply anything by roughly a thousand, which is why one grain per chessboard square ends as more rice than the world has grown.
Let’s go →One giant number spoils it
Why Is the Average Sometimes a Lie?
One extreme value drags an average a long way and leaves the middle value untouched. Which of the two is honest depends on the question being asked.
Let’s go →Making any amount
Why Do Coins Have Different Values?
Coin values follow a 1-2-5 pattern so that a handful can build any price out of very few coins. Their worth comes entirely from agreement.
Let’s go →Many equal groups
What Does Multiplying Do?
Multiplication is adding the same number over and over, compressed into a single move — which is exactly why the times tables are worth knowing by heart.
Let’s go →Numbers as places
What Is a Number Line?
Lay the numbers out in order and arithmetic turns into walking. Adding steps right, subtracting steps left, and suddenly negatives have somewhere to live.
Let’s go →Out of a hundred, always
What Does Per Cent Actually Mean?
Half a class of eight and half a school of eight hundred are the same share and wildly different numbers of children. The hundred is just a yardstick.
Let’s go →The fence and the field
How Are Area and Perimeter Different?
One is a length in plain metres and the other a count of squares, so the very same fence can enclose wildly different amounts of field.
Let’s go →Not everything scales
How Do You Double a Recipe?
Doubling a recipe doubles the ingredients and almost nothing else. The pan, the time and the temperature all have to be reconsidered separately.
Let’s go →The bit left over
What Is a Remainder?
Make as many equal groups as you can and the bit that will not fit is the remainder. It is not a mistake — it is the honest answer to an uneven split.
Let’s go →Close enough, on purpose
Why Do We Round Numbers?
Rounding deliberately gives up a little accuracy to get a number you can actually hold in your head. Do it at the end of a sum, never at the start.
Let’s go →Faster than one at a time
Counting in Jumps
Counting in twos, fives or tens moves in equal jumps instead of single steps. It gets you there faster, and it quietly builds the times tables.
Let’s go →One triangle, three questions
How Long Will the Journey Take?
Speed, distance and time are one relationship asked three different ways. Rearrange it for whichever you are missing, and make sure the units agree first.
Let’s go →Sharing, with an awkward remainder
How Do You Split a Bill Fairly?
Splitting a bill is straightforward division until the remainder appears. At that point it stops being arithmetic and becomes a question about people.
Let’s go →What is left
What Does Taking Away Do?
Subtraction does two jobs with one operation. It finds what is left after some is taken away, and it measures the gap between two numbers.
Let’s go →Counting without losing your place
Why Count in Groups of Five?
Tally marks bundle counts into fives so that you record one event at a time and add up groups at the end, instead of recounting from the beginning.
Let’s go →Shortcuts, not memory
What Patterns Hide in the Times Tables?
Four times six is a rectangle of counters, not a phrase to recite — and every answer in the nine row has digits that add up to nine.
Let’s go →Ten per cent, then adjust
How Do People Work Out a Tip in Their Head?
Nobody calculates a tip exactly. You move the decimal point one place to get ten per cent, build the rest from that, and round to something friendly.
Let’s go →The number under the price
Which Packet Is Actually Cheaper?
Divide the price by the amount and two packets become comparable at last. The catch is that the cheaper unit price only counts if you actually use it all.
Let’s go →Stacking layers of squares
How Much Does a Box Actually Hold?
Volume counts the cubes that would fill a space. Tile one layer, then stack that layer as many times as the height allows, and you have the answer.
Let’s go →A number your eye reads first
Why Does Everything Cost £4.99?
People read the leftmost digit first and round the rest away, so a price of 4.99 gets quietly filed in memory as four. Shops have known this for a century.
Let’s go →Space
Crashy night-sky stories — 2 stories.
All space →Further than you think
How Far Away Is the Moon?
The Moon sits about 384,000 km away — a gap wide enough to line up every other planet in the solar system, side by side, with room to spare.
Let’s go →Bigger than your brain wants
How Big Is the Sun?
109 Earths would span the Sun's face and 1.3 million would fill it. It holds 99.8% of everything in the solar system, and among stars it is ordinary.
Let’s go →Earth & sky
Weather, light, and the air around us — 1 story.
All earth & sky →How things work
Everyday machines, taken apart — 1 story.
All how things work →