what is maths and where does it go?

Twitter : @CountOnUsEd

Learning Together

Session 5

Thursday 18th June 10:00

Decimals

#npfsmaths

Learning Together Session 5 Decimals:

• What is a decimal• Place value• Understanding decimals• Decimals link to fractions• Ordering decimals


What is a decimal?


What is a decimal?

Decimals are numbers that exist between whole numbers.


How many coloured blocks are there

2



4



3



2 1

2



2 1

10


What decimal fraction is shaded

100 1 2 3 4 𝟓 7 986

1

2= 0 • 5

0 • 5

= 0• 5

1

2

5

10= 0 • 5

1

2

= 0• 5

0 • 5

What decimal fraction is shaded



100 1 2 3 4 𝟓 7 986

1 1

2=1 • 5

1 • 5

The decimal point separates the whole number part from the fractional part



100 1 2 3 4 𝟓 7 986

6 1

2=6 • 5

6 • 5


1

=0.11

10

Ones Tenths

0 1


10 0 • 1 0 • 2 0 • 3 0 • 4 𝟎 • 𝟓0 • 7 0 • 90 • 80 • 6

0 • 1

0 • 2

0 • 3

0 • 4

0 • 5

0 • 6

0 • 7

0 • 8

0 • 9

1 • 0

1 • 0

11

10= 0•1

2

10= 0• 2

3

10= 0• 3

4

10= 0• 4

5

10= 0• 5

6

10= 0• 6

7

10= 0• 7

8

10= 0• 8

9

10= 0• 9

10

10= 1• 0


1

Ones TenthsOnes Tenths

0 4

4

10= 0 • 4


1


0 9

9

10= 0 • 9



1 6

16

10= 1 • 6



1 4

10=1 • 4

100 1 2 3 4 𝟓 7 986



2 7

10=2 • 7

100 1 2 3 4 𝟓 7 986



9 8

10=9 • 8

100 1 2 3 4 𝟓 7 986

All slides and resources can be found atwww.countonus.org.uk/learning-together

http://www.countonus.org.uk/learning-together


1


the shaded section = 0 • 3

10 0 • 1 0 • 2 0 • 3 0 • 4 𝟎 • 𝟓0 • 7 0 • 90 • 80 • 6

1 • 0

More decimal numbers exist in between0 and 0•10•1 and 0• 20• 2 and 0• 3 … . .etc


What does the shaded section represent here?

1

100

1

100= 0 • 01

Ones Tenths Hundredths

0 0 1



0 0 1

1

100= 0 • 01

3

100= 0 • 03


0 0 3



0 0 3

3

100= 0 • 03

8

100= 0 • 08



0 0 8

8

100= 0 • 08

10

100= 0 • 10

1

10= 0 • 1

1

10=

10

100= 0 • 1 = 0 • 10



0 1 0

10

100= 0 • 10


0 2 3

23

100= 0 • 23


0 2 3

3

100= 0 • 03

2

10= 0 • 2

0 • 2 + 0 • 030

= 0 • 23

45

100


0 4 5

4

10

5

100

98

100


0 9 8

9

10

8

100


1

10

1

1001

= 0 • 1 = 0 • 01


Ones Tenths HundredthsOnes Tenths Hundredths

1 3 4




1 4 8



1 6 9




2 3 1




2 1 4




5 3 4



2 6 3


1 2 2


3 8 5TOTAL =


0 • 2

Ordering decimalsPut these decimals in order of size smallest to biggest

0 • 17 0 • 3 0 • 33

0 • 03

When ordering decimals it is helpful to have all the decimals with the same number of decimal places (pad with zeros to help)


0 • 2𝟎


0 • 17 0 • 3𝟎 0 • 33

0 • 03


0 • 03 0 • 17 0 • 2𝟎 0 • 3𝟎 0 • 33


0 • 17


0 • 7 0 • 79 0 • 007

0 • 07



0 • 17𝟎


0 • 7𝟎𝟎 0 • 79𝟎 0 • 007

0 • 07𝟎


0 • 007 0 • 07𝟎 0 • 17𝟎 0 • 7𝟎𝟎 0 • 79𝟎


Adding Decimals 0 • 9 + 0 • 6


Adding Decimals 0 • 9 + 0 • 6

1 • 5


Adding Decimals

James has a piece of wood that measure 0.8m. He joins another piece that is 0.5 m long. How long is the new piece?

𝟎 • 𝟓 1• 𝟎 1• 𝟓0

0• 𝟖


Adding Decimals

James has a piece of wood that measure 0.8m. He joins another piece that is 0.5 m long. How long is the new piece?

𝟎 • 𝟓 1• 𝟎 1• 𝟓0 1• 𝟑𝐦0• 𝟖


Slides and resources atwww.countonus.org.uk/learning-together/

#npfsmaths

https://www.countonus.org.uk/learning-together/


Slides and resources atwww.countonus.org.uk/learning-together/

#npfsmaths

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Follow us on Twitter and Facebook@CountOnUsEd

https://www.countonus.org.uk/learning-together/

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https://www.surveymonkey.co.uk/r/learningtogetherfeedback


0 • 02 × 10

= 0 • 2

Multiplying decimals by 100 • 02


0 • 03 × 10

= 0 • 3

Multiplying decimals by 100 • 03


0 • 07 × 10

= 0 • 7

Multiplying decimals by 10


0 • 02 × 100= 2

Multiplying decimals by 100

10 20 30 40 50 60 70 80 90 100

• 000 • 02 × 100 = 2

How would you do 90 + 50

90 + 10 + 40140


How would you do £0•90 + £0•50

£0•90 + £0•10 + £0•40£1•00 + £0•40

£1•40


Draw 9 dots in the 1st 10 frame

Twitter: @CountOnUsEd www.countonus.org.uk #NumeracyBluePrints [email protected]

£1.00 £1.40£0.90

+£0.40+£0.10


100 1 2 3 4 𝟓 7 986


£1

= 10p


£1

10p

20p

30p

40p

50p

60p

70p

80p

90p

100p


£1

£0.10


£1

£0.10

£0.20

£0.30

£0.40

£0.50

£0.60

£0.70

£0.80

£0.90

£1.00

= £1.20

= £2.30


= £1

= £0.18

= £0.82


= £11p= £0.01

what is maths and where does it go?

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