Lessons · Time and the sky
A month of moons
Draw the moon every night for a month. It takes twenty-nine and a half nights to come back to where it started, and no calendar teaches that as well as twenty-nine drawings in a row.
When
Any month of the year
Outside
About 5 minutes
What it teaches
Counting a long sequence, keeping a record, and meeting a cycle that is not seven days long.
What is going on
The moon takes twenty-seven and a third days to go round the earth, but twenty-nine and a half days to get back to the same shape, because the earth has moved along its own orbit in the meantime and the sunlight is coming from a different angle. That gap is why a lunar calendar drifts against a solar one and why every culture that used the moon needed a correction. The other half of the lesson is simpler and stranger: the moon is up in the daytime for about half of every month, plainly visible in a blue sky, and most adults have never once noticed it.
What to look for
- The daytime moon. A waxing moon is up in the afternoon; a waning one in the morning
- Which side is lit. The lit side always points at the sun, wherever the sun happens to be, including below the horizon
- Earthshine — the dark part of a thin crescent faintly visible, lit by sunlight bouncing off the earth
- How much later it rises each night. Roughly fifty minutes, which is why it seems to disappear for a week
First, outside
What to do
What to take
- A long strip of paper, or a grid of thirty squares
- A pencil
- A dark pencil or charcoal for the shadowed part
- 1
Rule thirty squares. Number them.
- 2
Every clear night, go out, look at the moon, come in and draw it in that night's square. Cloudy nights get a cloud — the gaps are part of the record.
- 3
Do not skip the daytime moon. It is up in daylight for half of every month and most people never notice.
- 4
At the end, hold the strip at arm's length and look at the shape the month makes.
Out loud
What to say to each of them
All three at once, off the same bucket of acorns. Read down the column that matches the child in front of you.
2
Point and name
- “Moon! Point at the moon. Is it a circle or a banana?”
- “Draw a circle. That's the moon.”
- “Say goodnight to the moon. Tomorrow we look again.”
Subitising — seeing that a group is two without counting it — and the idea that a number word belongs to a thing you are touching.
4
Count and compare
- “Is tonight's moon fatter or thinner than last night's?”
- “How many nights have we drawn so far? Count the squares.”
- “How many squares are left before the strip is full?”
One-to-one correspondence: one number word per object, the last word you said is how many there were. Then more, fewer, and the same.
6
Tally and figure
- “From full to full is about twenty-nine and a half nights. How many is that shorter than a month of thirty-one days?”
- “Count the nights from new moon to full. Now count full back to new. Are they the same?”
- “Which half of the month was the moon up in the daytime?”
Grouping as a way of counting past what fingers hold, and subtraction as the distance between two numbers rather than a taking-away.
When it is not working
What going wrong looks like
Most of what looks like failing is a child standing at a known place on a known ladder. Knowing which place changes what you do next, and it is usually not more practice.
About 2
Draws a circle every night regardless. Good. The habit of going out and looking is the whole of it at two.
About 4
Draws the crescent facing whichever way is easiest to draw. Stand beside them and point at the real one; direction is half the record.
About 6
Gives up on the cloudy nights and abandons the strip. Mark the gaps as clouds and keep going — a record with honest holes in it is a record, and a record with invented nights is not.
How you know it landed
They spot the moon in daylight and tell you, unprompted, before you have seen it.
Rungs of the ladder this builds
Then, five minutes on screen
The same idea, drilled
Quick counting, for the nights the sky is solid cloud.
Why this order
The walk first, the game after. Reversed, the walk becomes the price of the game, and a child who has learned that outside is what you do before the screen has learned the wrong thing very efficiently.
The answer key
The next thirty nights
The real shape for every night of the coming month. Check the strip against it, see when the full moon lands, or work out on a cloudy Tuesday what would have been drawn.
A month of moons
The next 30 nights
Count the nights along to the round one. Was it 4?
Tap a night to read it. The gold ones are the full and the new moon — the two nights the month is measured between.
When you have done it
Ticking it keeps it off the next season plan, and nothing else.
We look, we count and we put it back. Nothing goes in a mouth — not a berry, not a mushroom, not a leaf. That is the whole rule, and it is the same rule every time.
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