1 - Getting Started ~3 mins
Look at the board. Someone has written a number for fourteen: 41.
What do you notice? What were they thinking?
2 - Watch and Notice ~8 mins
A teen number is from 11 to 19. Each one is one full ten and some more.
We say four-teen and hear four first. But fourteen is still one ten and four extras, sitting just past 10 on the line.
We write digits (number symbols) as 1 for the full ten first, then 4 for the extras: 14.
41 is those digits swapped. Watch each teen on the line: the ten always writes first.
3 - Try It Together ~8 mins
We try teen numbers together on the line.
One pupil at the board sets the digit cards in order — 1 for the ten first — then drags the marker. Everyone else writes the digits big in the air: ten first, then how many more.
We will try 12, then 15, then 17, then 19.
Place the teen number
4 - Write Teens in Your Copy ~5 mins
In your maths copy, carefully write these teen numbers in one line. Start each with the 1 for the ten.
- 11
- 12
- 14
- 16
- 18
- 19
If you finish, use the Teen Numbers Practice sheet for the other teens and the fix-the-swap pairs (such as 41 or 14).
5 - Class Challenge ~8 mins
We place teen numbers on the line together.
One pupil drags the marker. Everyone else says the number and writes the digits in the air — ten first — then we check together.
Place thirteen, then fifteen. Next: someone wrote 41 for fourteen — place the real fourteen. Last: place the number that is a ten and seven more.
Place the teen numbers
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