calculation up to 100; nied okahandja - advisory teachers - october 2013

Presentatie titel

Rotterdam, 00 januari 2007

Calculation up to 100

Okahandja, October 2013

Teaching materials

1 All kind of counting materials

Teaching materials

2 10-frames

Teaching materials

2 10-frames

1 1 1 2 1 3

Teaching materials

3 Classroom number line 1 - 100

Teaching materials

5 100-beads/bottle caps string

Teaching materials

7 Empty number line

Teaching materials

6 Sun-game

Strategies calculation up to 100

43 + 35 =

58 + 26 = 

85 – 32 = 

72 – 37 =

SolveSolve the problems and write down your calculations.

Show the way you find your answer!

The calculations of the learners of Elim Primary School in Windhoek

The calculations of the learners of Elim Primary School in Windhoek

The calculations of the learners of Elim Primary School in Windhoek

The calculations of the learners of Elim Primary School in Windhoek

The strategies used by the learners of Elim Primary School in Windhoek

In grade 3:Counting one-by-one,Stepwise addition and subtraction/ Stringing,Splitting,Digit algorithm

In grade 4:Stepwise addition and subtraction/ Stringing,Splitting,Digit algorithm

In grade 5:Digit algorithm

Strategie 1: Counting one-by-one

Counting or calculating?

Strategie 1: Counting one-by-one

Teaching materials

All kind of counting materials

Strategie 2: Stepwise addition and subtraction/Stringing

45 + 28 =Joan has read 45 pages inher book.Today she reads 28 pages.

45 + 20 = 6565 + 25 = 70 70 + 23 = 73

Strategie 2: Stepwise addition and subtraction/Stringing

84 – 27 =I cut 27cm off a ribbon measuring 84 cm. How much is left?

Strategie 2: Stepwise addition and subtraction/Stringing

50 – 36 =I spent 36p in a shop. How much change did Iget from 50p?36p + ____p = 50p

Counting on using a number line is particularly useful in calculating change.

‘Shopkeepers strategy’

Strategie 2: Stepwise addition and subtraction/Stringing

47 + 2547 + 3 = 50,50 + 20 = 70,70 + 2 = 72

47 + 25 47 + 20 = 67,67 + 3 = 70,70 + 2 = 72

47 + 25 47 + 20 = 67,67 + 5 = 72

Strategie 2: Stepwise addition and subtraction/Stringing

Teaching materials

Numberline Sun-game 100-beads/bottle caps string Empty number line

Strategie 3: Splitting or Column calculation

47 + 2540 + 20 = 60,7 + 5 = 12,60 + 12 = 72

Strategie 3: Splitting or Column calculation

44 + 2540 + 20 = 60,4 + 5 = 9,60 + 9 = 69

4425 +60 9 +69

Strategie 3: Splitting or Column calculation

def(icit)

Strategie 3: Splitting or Column calculation

Teaching materials

10-frames bundles of sticks

Strategie 4: Digit algorithm

Which strategie do you choose?

A book with 84 pages.You are reading at thebottom of page 37.How many pages still toread?

The black t-shirt costs N$ 92 and the grey t-shirtcosts N$ 69.How much more expensiveis the black t-shirt?

N$ 92 N$ 69

The basic strategies: 1 Stepwise addition and subtraction/ Stringing

Starts with flexible countingThe ‘large number line’: 10 – 20 – 30 – 40 – 50 – 60 – 70 – 80 – 90 – 100The ‘small number line’: 1 – 2 – 3 – 4 - 5 – 6 - 7 – 8 – 9 – 10 – 11 – 12 - ….- 33 – 34 – 35 – 36 – 37 – 38 – 39 - 40- etcUse of the empty number line as a ‘notation scheme’ and ‘paradigm’

The basic strategies: 2 Splitting/ column calculation

Starts with place valueUse of the 10-frames as a ‘paradigm’Use of the ‘column notation scheme’ emphasises the place value

The teaching-learning-trajectory

Basic strategies for all learners:

Stepwise addition and subtraction/ StringingSplitting/Column calculation

Additional:Smart calculation

Exercises

46 + 23 =58 + 36 =76 – 24 =63 – 28 =

Stepwise stinging (shopkeepers method), Stepwise splitting,

Discussion

What materials are you using now in computation up to 100?

What strategies do you teach in computation up to 100?

Do you see a relationship between computation up to 20 and computation up to 100? Please, explain.

Studies

Teaching-learning trajectory ‘stepwise addition and subtraction,

Teaching-learning trajectory splitting

Teaching-learning trajectory smart calculation

Studies

How does it start?Which steps for the learners to make in the learning trajectory?Which teaching materials are usefull in the teaching trajectory?Which notation schemes do the learners use?What are the learning outcomes in this teaching learning trajectory?

Please, make the materials yourself

Use the materials and discover the possibilities to teach mathematics with these ‘easy to make’ teaching materials!

Jaap Griffioen – j.griffioen@hr.nl Jaap de Waard – j.de.waard@hr.nl

The 100-caterpillar

Choose two different numbers between 0 en 100, Put these numbers in order in the first and the

second part of the caterpillar, Make the number in the next part by adding the two

previous numbers, The number in the fifth part must be 100!

100

75-game5 10 15 20 25 30 35 40 45

Player 1

Player 2

Rules of the game:

Take a turn to a number,

Choose from the numbers 5, 10, 15, 20, 25, 30, 35,40, 45,

Each number can be chosen only once!

Do you have three numbers which together have 75? You are the winner!