Look at the board. Someone has written a number for fourteen: 41.
What do you notice? What were they thinking?
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.
Build each teen on your two ten-frames. Fill the first frame first: that is the ten. Put the extras on the second frame.
Here is 14: one full ten and 4 more. The 1 for the ten writes first, then the 4.
Point at your full frame and say one ten. Point at your second frame and say how many more. Write the number big in the air, ten first. Then one of us puts the marker on the number line.
We will try 12, then 15, then 17, then 19.
Place the teen number
In your maths copy, carefully write all the numbers from 11 to 20, in order. Start every teen with the 1 for the ten.
- 11
- 12
- 13
- 14
- 15
- 16
- 17
- 18
- 19
- 20
The last one is 20. It starts with a 2 because it is two full tens.
Unlock the full learning experience
You're previewing this lesson. Get full access to this lesson and hundreds more — each one ready to teach, with interactive activities, printable resources and pupil progress tracking built in.
This lesson is copyright of 123Learn.ie 2017 - 2026. Unauthorised use, copying or distribution is not allowed.