Kindergarten · Ages 5–6
The Ordering Year
The tell at five is not counting high. It is counting in order when nobody asked them to — and noticing when they skipped one.
- 1 Hard Thing
- 5 days · 85 minutes
- 3 unmarkable questions
The Hard Thing · about a grade above
Every Way to Make Ten
Find every pair of numbers that adds up to ten. Not some of them — all of them. Then prove to somebody that you did not miss one.
Stuck for ten minutes? Good. Open one hint, not three.
1Hint 1
Start with 0 + 10. What comes next?
2Hint 2
Write them one under the other. Does the first number in each line do something you recognise?
3Hint 3
You can stop when the first number reaches 10. Work out why that is allowed.
The answer — only after you have written something down
Eleven pairs, if 0+10 and 10+0 count as different: 0+10, 1+9, 2+8, 3+7, 4+6, 5+5, 6+4, 7+3, 8+2, 9+1, 10+0. You know none are missing because the left-hand number climbs by exactly one every line and never skips.
The genius move
“Go in order, and the proof comes free.”
Five days, five muscles
The week
Never the same muscle two days running. The weekend is not on this list on purpose — being bored is the sixth muscle and it needs two clear days.
- MondayThe Hard Thing
Every Way to Make Ten. Stop at twenty minutes even if it is not finished.
20 min - TuesdayBuild
Make each pair out of real objects and photograph it. The photos become a strip they can point at.
20 min - WednesdayRead up
A book a year above them, read by you, with one word a page they guess from the picture.
15 min - ThursdayTeach
They teach the ten-pairs to a toy, out loud, badly. Do not correct it.
10 min - FridayBreak
Give them a pattern with one mistake in it. Their job is to find the mistake — not to fix it.
20 min
Start Monday now
Read the problem once more, out loud, and press start. Solving it is not the measurement.
Nothing rung today yet
The twenty-five minutes
Four phases. The middle one is most of it, and it is meant to feel slow.
- 1SitRead the problem again, out loud. Write nothing yet.
- 2AttackTry the wrong thing. It is faster than thinking about the right one.
- 3StuckWrite down the exact place you are stuck. “I don’t get it” is not a place.
- 4LogOne sentence: what you will try tomorrow. Then close the book.
No answer key
Three questions you cannot mark
Ask one at dinner. Do not resolve it. A question that survives the washing-up is doing its job.
- ?1
Is zero a number, or is it nothing?
- ?2
What is the biggest number that has a name?
- ?3
If you count forever, do you ever finish?
Where this goes
The ladder
The same idea, three times, roughly a year apart. This is what depth looks like from the outside.
This year
Pairs that make ten, listed in order.
Next year
Pairs that make twenty — and the moment they notice it is the same eleven with a ten stuck on the front.
The year after
Three numbers that make ten. A much longer list, and the first time going in order really earns its keep.
What lives on the desk this year
- Ten of something identical — pegs, cubes, coins
- A strip of paper long enough for eleven lines
- A pencil that will not need sharpening mid-thought
- A number line on the wall at their eye height
- A drawer they are allowed to raid without asking
The rest of Kindergarten
One hard thing a day is the sharp end. It sits on top of an ordinary year.
Last updated: September 2026