Transcript Year 5 Term 2 Unit 7

Year 5 Term 2 Unit 7
Day 2
L.O.1
To be able to use doubling to multiply twodigit numbers by 4.
To halve any two-digit number.
We are going to double these numbers:
63
18
52
56
47
66
27
77
39
98
95
41
We are going to halve these numbers:
64
78
52
42
20
48
74
50
66
32
96
22
If we halve these numbers how can
we express the answers?
Will they be fractions or decimals?
23
87
65
93
31
47
59
75
19
24
Q. What is a quick way to multiply
this number by 4?
Doubling twice is the quick mental method to
multiply by four.
We’ll multiply each of these aloud by 4.
23
18
55
87
34
76
39
L.O.2
To be able to understand area measured
in square centimetres.
To understand and use the formula in
words “length x breadth” for
the area of a rectangle.
cm²
We used cm² to find the areas of shapes in yesterday’s lesson.
Here we have a square metre.
1metre
How many cm² are
there in I square
metre?
How can we work it
out?
1metre
1m²
1m² = 10 000cm²
because
and
and
length = 100cm.
breadth = 100cm.
100cm x 100cm = 10 000cm²
1mm²
Try to imagine a millimetre square
Q. How many mm² are there in 1cm²?
Q. How can we work it out?
1cm² = 100mm²
because
length = 10mm
and
breadth = 10mm
and 10cm x 10 cm = 100mm²
Which of the three units ( m² ,cm² , or mm²)
would be best for measuring these?
1.
2.
3.
4.
5.
6.
7.
The classroom floor.
An exercise book.
A postage stamp.
The playground.
A chocolate bar wrapper.
A mouse mat.
Your thumbnail.
.
2.8 cm
6.1 cm
The area of a rectangle is length x breadth or l x b for short.
Here the area would be 6.1 x 2.8 but it is useful first to get an
ESTIMATE
Q. What is the approximate area of the rectangle?
.
2.8 cm
6.1 cm
Rounding UP and DOWN leads to an approximate area of
6 x 3 = 18cm²
Let’s try with these:
1.
1.7cm
5.9 cm
Rounding UP and DOWN leads to
2.
6cm x 2 cm = 12cm²
3.2cm
11.8cm
Rounding UP and DOWN leads to 12cm x 3 cm = 36cm²
.
With a partner complete
Activity Sheet 7.1
. In which rectangles do you
think the area has been
underestimated?
Using calculators we’ll check
your estimates but will round
part-answers to the nearest
whole number.
Q. What areas of shapes in
the classroom would you
measure in mm², cm², or m²?
Record about a dozen
altogether.
In your book draw rectangles using cm and mm and
write their length and breadth. Be accurate!
Your partner must first estimate the area by rounding up
or down then work out the area to the nearest whole
number using a calculator.
Record both the estimate and the final answer.
Tetrahedra draw 2
Spheres draw 3
Prisms draw
4
Extension: measure area to two decimal points.
By the end of the lesson children should
be able to:
Express the formula for the area of a
rectangle first in words then in
letters.
Choose a suitable unit to estimate the
area.
Year 5 Term 2 Unit 7
Day 3
L.O.1
To know what each digit represents in a
number with up to two decimal places.
To be able to round decimals to the nearest
whole number.
This is our number line.
I need a volunteer to show each of these numbers:
0
1
3.7
6.8
2.4
8.1
7.2
5.9
1.6
4.5
2
3
4
5
6
7
8
9
10
Now I need volunteers to identify to one
decimal place each of the points arrowed.
0
1
2
3
4
5
6
7
8
9
10
REMEMBER……
How we round numbers to the nearest whole
number…..
Identify the value to one decimal point of each number
arrowed, round it to the nearest whole number and
write both in your books.
0
1
2
3
4
5
6
7
8
9
10
.
Q. Which numbers do the arrows represent?
Red
Blue
Purple
Brown
Orange
Green
1
3
.
Q. Where would these points fit on the line?
1.42
2.73
1.81
2.68
1.57
2.33
1
1.2
1.7
2
2.3
2.5
2.8
3
Round these to the nearest whole number.
Write answers in your book.
3.57
2.49
34.67
191.53
2456.98
5.86
93.21
6.67
57.85
1.08
86.55
234.62
777.50
7107.51
5864.45
L.O 2
To be able to understand, read and write
standard units for mass including their
abbreviations (kg. g.) and relationships
between them.
To be able to convert kg. to g.
To be able to record estimates and readings
from scales to a suitable degree of accuracy.
We are investigating MASS not weight since the
mass of an object does not vary but its weight
will change depending on where it is weighed.
Weight decreases with altitude!
We shall learn to use decimal notation for
recording mass in kilograms.
1000g
A
This counting stick represents a
scale for the range 0 to 1000g.
Q. How many grams does each
division represent?
B
C
0g
Q. What is the value of the point
indicated by the red arrow.
Q. What are the values shown by
the other arrows?
1000g
A
Q. What value does the red arrow
indicate here?
1. to the nearest division
2. exactly
B
C
0g
Q. What values do the other arrows
show?
1000g
Q. How many kg are equivalent to 1000g.
REMEMBER…
KILO means a thousand
Q. What fraction of 1kg does each
division represent.
0g
1000g
Each division represents
1/10 of 1 kg.
or
0.1 of 1 kg.
If I write
0.5 kg.
what does it mean?
0g
1000g
0.5 kg = ½ kg = 5/10 kg = 500g
Copy and complete this table:
0g
0.25 kg =
=
=
0.75 kg =
=
=
0.9 kg
=
=
0.3 kg
=
=
0.6 kg
=
=
2000g
A
This counting stick now represents a
scale for the range 0 to 2000g.
Q. How many grams does each
division represent?
B
C
0g
Q. What is the value of the point
indicated by the red arrow.
Q. What are the values shown by the
other arrows?
2000g
A
Q. What value does the red arrow
indicate here?
1. to the nearest division
2. exactly
B
C
0g
Q. What values do the other arrows
show?
100g
Each division now represents 10g.
so the scale represents
100g.
Q. If each division changed so
it became:
5g
1g
2g
what ranges would the scale
represent?
0g
1.25 kg
How can we write this in kg and g; then in g?
REMEMBER…
The first decimal place represents tenths of a
kilogram and the second hundredths.
Whole kilograms
.
tenths hundredths
1.25 kg
Copy and complete this table in your books.
kg
1.25 kg
1.5 kg
kg and g
1kg 250g
g
1250g
1kg 900g
0.7 kg
1kg 750g
380g
0.24 kg
2040g
Q. How do we convert kilograms into grams?
Answer….
Q. How do we convert grams into kilograms?
Answer….
Q. Which rows of the table were the most difficult
to complete? Why?
Answer….
Complete this list of 8 objects at home:
Item
Bag of sugar
Weight in g
2200g
Weight in kg
2.2kg
By the end of the lesson the children should
be able to:
Use correctly the abbreviations g and kg.
Understand and use the relationship
between g and kg.
Know the equivalent of one-half, one-quarter,
three-quarters, one-tenth and onehundredth of a kilogram in grams.
Year 5 Term 2 Unit 7
Day 4
L.O.1
To be able to convert kg to g.
1 kg
Q. How many grams in 1 kg?
A
B
Q. What mass does the red arrow represent?
Q. How else can we express this mass?
(3 ways)
0g
C
Q. What mass is represented by each of the
other arrows?
D
Q. How else can we express this?
1 kg
D
Q. What mass does each of the black arrows
represent?
Q. How else can we express this mass?
C
B
Q. What mass is represented by each of the
green arrows?
Q. How else can we express this?
A
0g
L.O.2
To be able to record estimates and
readings from scales to a suitable
degree of accuracy
100g
A
B
C
D
E
This is a LINEAR scale
Q. What is the value of each interval?
Q. What value does each of the arrows indicate?
200g
A
B
C
D
E
Q. Now what is the value of each interval?
Q. Where would 60 g appear?
Q. Where would 130 g appear?
Q. What value does each of the arrows indicate?
400g
A
B
C
D
E
Q. What is the value of each interval now?
Q. What value does each of the arrows indicate?
Q. Where does 300 g appear?
800g
A
B
C
D
E
Q. What is the value of each interval now?
Q. What value does each of the arrows indicate?
Q. Where does 500 g appear?
Q. Where have
you seen a
scale like this?
B
A
Q. What is the
difference
between this
scale and the
last one?
C
500g
This is a CIRCULAR scale
Q. What is the value of each interval?
Q. Which values are indicated by the arrows?
Q. What is the
difference
between this
scale and the
last one?
B
A
C
2 kg
Q. What is the value of each interval?
Q. Which values are indicated by the arrows?
100g
A
B
This scale is much finer than the first linear one we looked at.
Q. What is the value of each large and each small marker.
Q. Where would 40g, 65g and 87g appear?
Q. What values are indicated by the arrows?
50g
A
B
Q. What are the markers worth now?
Q. Where would 30g, 12.5g and 47.5g appear?
Q. What values are indicated by the arrows?
Now for Activity Sheet 7.2
With a partner discuss which is the lightest and
the heaviest mass of those shown then the order
of those in between. Write the correct order in
your book starting with the lightest.
1.1 kg
650g
375g.
1040g
1.25 kg
0.7kg
0.3kg.
If you finish quickly make a list of different masses for your
partner to put in order.
Tetrahedra up to 2kg
Spheres up to 5 kg
Prisms
up to 10 kg.
By the end of the lesson the children should
be able to:
Use the relationships between metric units
and mass
Read scales between divisions
Record estimates and readings from scales.
Year 5 Term 2 Unit 7
Day 5
L.O.1
To be able to multiply and divide any
positive integer up to 10 000 by 10 or 100
and understand the effect.
This pencil weighs 5g.
Q. What would be the weight of this number of
pencils?
10
100
Can you see an object in the class which
might weigh the same as 10 pencils?
We’ll weigh it to see.
Q. How close to the weight of 10 pencils is
the weight of the object?
Q. What would be the weight of this number
of objects?
10
100
Can you see an item in the class which might
weigh the same as 10 of these objects?
We’ll weigh it to see.
Q. How close to the weight of 10 objects is
the weight of the item?
Q. What would be the weight of this number of
items?
10
100
Q. What is the effect of multiplying a number by 10 or by
100 on the position of the digits?
Q. What is likely to be the effect on the digits of dividing a
number by 10 or 100?
Q. If 100 rulers weigh about 1550g what would
be the weight of this number of rulers?
10
1
.
This ruler weighs 15g.
What would be the weight of this number of rulers?
10
100
We will find the weight of two other objects in the
classroom then multiply to find the weight of 10
then 100 of them.
Object A
1 weighs
10 weigh
100 weigh
Object B
1 weighs
10 weigh
100 weigh
If 1000 smarties weigh 1200 g find the weight of:
100
10
If 100 empty C.D. cases weigh 375 g find the weight of:
10
1
If 1000 pairs of scissors weigh 22kg find the weight of:
100
10
1
L.O.2
To be able to record estimates and
readings from scales to a suitable
degree of accuracy.
To be able to suggest suitable units and
measuring equipment to estimate or
measure mass.
From the work you have done you should be able to identify
the weight of each of these familiar items:
Tin of beans
Sliced loaf
Tub of margarine
Chocolate bar
Packet of crisps
Packet of sugar
Box of cereal
Q. What is the common unit of measurement?
Q. Which have the greatest / smallest difference in weight?
Q. What do we call 1000g?
1000g is called 1kg
Kilo means “1000 of ”
There are kilometres, kilolitres, kilowatts,
kilograms and other units in “kilo”s.
Q. What do metres and kilometres measure?
Q. What do litres and kilolitres measure?
Metres and kilometres ( m and km)
measure length or distance.
Litres and kilolitres ( l and kl )
measure capacity or volume.
Other abbreviations are cm and mm which
mean centimetres and millimetres
and
cl and ml which
mean centilitres and millilitres.
centi means one hundredth
milli means one thousandth.
One bottle holds 1 litre and the other 2 litres.
Q. Does one bottle look twice the volume of the other?
Estimating capacity is difficult.
.
Q. What would one
kilolitre look like?
1
LITRE
1 kilolitre would be the equivalent of
1000 litre bottles of liquid or
500 2-litre bottles.
Q. Suppose you drank 5 litres of water a day
how long would it take to drink 1 kilolitre?
If you drank 5 litres of water a day it would take
1000 ÷ 5 = 200 days to drink I kilolitre.
200 days ÷ 7 = 28 weeks 4 days
- that’s over ½ a year!
Containers smaller than 1 litre are measured in
cl or ml e.g a can of cola.
COLA
Q. What is a medicine spoon measured in?
A medicine spoon holds 5ml which is a
very small amount.
Copy and complete the table
1l 45cl
145cl
1.45l
1450ml
117cl
1.38l
1l 66cl
1074ml
1.85l
Which of these values is the greatest / smallest?
4.75l
469cl
478cl
4.85l
4700ml
This number line runs from 1 litre to 2 litres.
Which values are indicated by the arrows?
answers in
l, cl and ml
1l
2l
A
B
C
D
E
This number line runs from 200cl to 400 cl.
Which values are indicated by the arrows?
answers in
cl, ml then l
400cl
200cl
A
B
C
D
E
By the end of the lesson children should be
able to:
Use correctly the abbreviations kl, l,
cl,ml;
Estimate and check using standard
metric units;
Respond to questions such as do you
think there is less or more than
1 litre of water in this jar?