The purpose of this unit is to recognise and understand teen numbers. This is an essential piece of knowledge for the part-whole strategy of bridging to ten.

recognise and understand “teen” numbers, 11-20.

### Number FrameworkStage

Advanced Counting (Counting on)

Pre-requisite knowledge / skills: form addition facts to ten using dot patterns on a quinary frame

Teacher hold up a full tens frame and asks*How many have I got?*

- Teacher holds up another card, alongside the full tens frame, and asks
*How many have I got now?* - Repeat several times ensuring that the numbers 11 – 20 have been covered.
- Teacher repeats above but this time shows the students the full tens frame has been turned over so the dots are not visible.
- Teacher models 11 on the tens frame.
*Let’s look at the number 11. How would we write that?*Records: 10 + 1 = 11 then works through 10 + 2 = 12, 10 + 3 = 13 etc similarly to show the pattern. - Teacher asks students to solve problems such as 10 + 4, 10 + 9 with a focus on quick recall.

### Extension Activities

Teacher models one of the teen numbers on a tens frame. Students record the written form “15” while one student uses the expanded numeral cards to record the number. Once the recording is finished teacher asks:*What does the 1 mean?* [1 group of ten]*What does the 5 mean?* [ 5 ones]

Teacher adds further blank tens frames to the model, for example 21: two tens and a 1.

Note: the context of a train with one full carriage and one partly full carriage can be used in this teaching sequence