1. Presentatie titel Calculation up to 20 Okahandja, June 2014
Rotterdam, 00 januari 2007

2. Teaching materials - Learners know all kinds of countable materials.
- Counting goes faster, if learners are
structuring these materials
- Structuring is the base for calculation!!

3. What materials will provoke to think in structures?
1 Number line

4. Number line 1 - 20 Orientation in the number range 1 – 20
5- and 10-structure
Counting in one’s, counting in fives
Even and odd numbers
Neighbours
Addition by counting on
Subtraction by counting back
Strategies: counting on, counting back

5. Teaching materials
2 Number snake

6. Number snake 1 - 20 Orientation in the number range 1 – 20
5- and 10-structure
Counting in one’s
Even and odd numbers
Neighbours
Number game with a die
Addition by counting on
Subtraction by counting back
Strategies: counting on, counting back

7. Teaching materials
3 ‘Numbers in love’, ‘Friends of 10

8. Numbers in love
Number bonds of 10
Complementing to 10

9. Teaching materials 4 10-beads string with 5-structure

10. 10-beads string with 5-structure
Orientation in the number range 1 – 10
5-structure
Counting in one’s
Addition by counting on
Subtraction by counting back
Calculating ‘via 5’
Reading the answer without counting
Strategies: counting on, counting back, ‘via 5’
Deze eruit

11. Teaching materials
5 10-frame

12. 10-frame Orientation in the number range 1 – 10 5-structure
Doubles structure, halves structure
Counting in one’s
Addition by counting on
Subtraction by counting back
Calculating ‘via 5’
Reading the answer without counting
Strategies: counting on, counting back, ‘via 5’

13. Teaching materials
6 20-beads string with
5-structure

14. 20-beads string with 5- and 10-structure
Orientation in the number range 1 – 20
5-structure and10-structure
Counting in one’s, counting in fives
Addition by counting on
Subtraction by counting back
Calculating ‘via 5’, calculating ‘via 10’
Reading the answer without counting
Strategies: counting on, counting back, ‘via 5’, ‘via 10’

15. Teaching materials
7 20-frame

16. 20-frame Orientation in the number range 1 - 10, 1 – 20
5-structure and 10-structure
Doubles structure, halves structure
Counting in one’s, counting in fives
Addition by counting on
Subtraction by counting back
Calculating ‘via 5’, calculating ‘via 10’
Calculating ‘with fives’, ‘with doubles’ and ‘with halves’
Reading the answer without counting
Strategies: counting on, counting back,
‘via 5’, ‘via 10’, ‘with fives, doubles and halves’

17. Strategies Materials with 5-structure: 10-frame, 10-beads string
5-problems
5 + 3 , 2 + 5
Splitting by 5
4 + 3 = =
5 + 2 = 7

18. Strategies Materials with 5- and 10-structure: Beads string & Friends of 10
Splitting by 10
‘via 10’
7 + 5 =
= = 12

19. Strategies Materials with 5- and 10-structure: 20-frame
Via 10
8 + 6 = =
= 14
Splitting in fives
6 + 7 = =
= 13
Doubles
4 + 4 = 8
6 + 6 = 12,
7 + 7 = 14
Nearly doubles
7 + 6 = =
= 13

21. Strategies Materials with 5- and 10-structure: 20-frame
Via 10
15 – 7 = 15 – 5 – 2=
= 8
Halves
8 - 4 = 4
= 6,
= 7
Nearly halves
= =
7 – 1 = 6
14 – 6 = 14 – = = 8

22. Summery of the strategies
Basics:
One more
Two more
Doubles
Friends of
Splitting by
Via ten
(based on the skill of counting in one´s and two´s)

23. Summery of the strategies
Basics:
One less –
Two less –
Halves –
Splitting by 5 –
Via 10 –
(based on the skill of counting in one´s and two´s)

24. Possibilities for exercise by playing games
Make 15
Guess my number
Make 10 (4 dices)

25. 15-game Rules of the game: Take a turn to a number,2 3 4 5 6 7 8 9
Player 1
Player 2
Rules of the game:
Take a turn to a number,
Choose from the numbers 1, 2, 3, 4, 5, 6, 7, 8, 9.
Each number can be chosen only once!
Do you have three numbers which together have 15?
You are the winner!

26. Various exercises calculation up to 20(1)
Waku waku??
Example:
Given numbers:
Assignment: Make 6 by addition, subtraction (later in grade 2 also
possible by multiplication and division)

27. Various exercises calculation up to 20(2)