## 32) Starting at Twenty: Using Numbers

Counting Backwards from 20

### Understanding Activity Instruction

This is an ‘understanding’ (proficiency strand) activity . It takes longer than other ‘fluency’ activities.

- Please allow 40 minutes for each session. These sessions are hard! The concept is hard. Organising the cards and blocks is VERY hard. Please plan for some down time after each session this week. The students, and you, will need it. Congratuations for surviving this week. It’s gets easier from here…promise!
- Don’t worry about getting the students to place the cards neatly. It will be a huge mess. Learning and developing resilence is a messy business. What’s important is that at the end of the year the students realise that ‘sixteen’ is this, 16 (not 61), and that the digit ‘one’ in
__1__6 is worth*ten*.

**Implementation Option A**

- Monday: Use Place Value Arrow Cards. Watch video “Activity 32: Using Numbers Session 1”. Say
*“tens then ones”*. - Tuesday: Use Place Value Arrow Cards. Watch video “Activity 32: Using Numbers Session 2”. Say
*“ten add __ is __”*. - Wednesday: Use Number Cards. Watch video “Activity 32: Using Numbers Session 3”. Say
*number names.*

**Implementation Option B**

- Monday: Use Place Value Arrow Cards. Watch video “Activity 32: Using Numbers
**Session 1**“. Say*“tens then ones”*. - Tuesday: Use Place Value Arrow Cards. Watch video “Activity 32:
**a little easier**” (scroll down to access). Say*“ten and __ is __”*. - Wednesday: Use Place Value Arrow Cards. Watch video “Activity 32: Using Numbers
**Session 2**“. Say*“ten add __ is __”*. - Thursday: Use Number Cards. Watch video “Activity 32: Using Numbers
**Session 3**“. Say*number names.* - Friday: Use Place Value Arrow Cards. Watch video “Activity 32:
**a little harder**” (scroll down to access). Write numbers.

**Setting Up Cards**

Please note, even though at the end of this activity students count backwards, I have chosen to set up the place value arrow cards and number cards in counting order. Using the cards is hard enough. “A little harder” version is to set up the cards using the counting backwards sequence.

### Mathematics

- Develop fluency counting backwards in the correct order from 20 to 10.
- Identify numbers from 11 to 19 as a two-part bond made of 10 plus a single-digit number.
- Connect the length of the Bond Blocks, number name and numeral.

### Language

- One shorter.
- One less than.
- One number before.
- A number is made up of digits in the same way a word is made up of letters. The number 16 is made up of the digits one and six.

Place value: The place of a digit in a number determines the digit’s value (worth). - In the number 16 the digit one is in the tens place so is worth one ten, ten.
- The digit six is in the ones place so is worth six ones, six.

## Differentiation

### A little easier

##### Implementation Option B

Many students benefit doing this week over five sessions, instead of three. This plan is listed above under the heading “Implementation Option B”.

This is the video for Tuesday. Watch it after the Session 1 video, before the Session 2 video.

See the Board 1 from the A Little Easier chapter.

### A little harder

##### Write the Number

Player One builds the number using the arrow cards, saying “tens, then one”.

Player Two writes and says the number.

##### AAA

P

##### AAA

P