Year 5 Term 2 Unit 7 Day 2. L.O.1 To be able to use doubling to multiply two-digit numbers by 4. To halve any two-digit number.

Year 5 Term 2 Unit 7

Day 2

L.O.1

To be able to use doubling to multiply two-digit numbers by 4.

To halve any two-digit number.

We are going to double these numbers:

63 18 47

52 66 39

56 27 98

77 95 41

We are going to halve these numbers:

64 78 20

52 48 66

42 74 32

50 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 55 34

18 87 7639

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.

cm²We used cm² to find the areas of shapes in yesterday’s lesson.

Here we have a square metre.

1metre

1metre 1m²

How many cm² are there in I square metre?

How can we work it out?

1m² = 10 000cm²

because length = 100cm.

and breadth = 100cm.

and 100cm x 100cm = 10 000cm²

1mm²Try 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. The classroom floor.

2. An exercise book.

3. A postage stamp.

4. The playground.

5. A chocolate bar wrapper.

6. A mouse mat.

7. Your thumbnail.

.

6.1 cm

2.8 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?

.

6.1 cm

2.8 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 6cm x 2 cm = 12cm²

3.2cm

11.8cm

2.

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 2Spheres draw 3Prisms 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.

0 1 2 3 4 5 6 7 8 9 10

This is our number line.

I need a volunteer to show each of these numbers:

3.7 6.8 2.4 8.1

7.2 5.9 1.6 4.5

0 1 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

Identify the value to one decimal point of each number arrowed, round it to the nearest whole number and write both in your books.

REMEMBER……

How we round numbers to the nearest whole number…..

.

1 3

Q. Which numbers do the arrows represent?

Red

Blue

Purple

Brown

Orange

Green

.

1 1.2 1.7 2 2.3 2.5 2.8 3

Q. Where would these points fit on the line?

1.42

2.73

1.81

2.68

1.57

2.33

Round these to the nearest whole number.

Write answers in your book.

3.57 2.49 5.86 6.67 1.08

34.67 93.21 57.85 86.55

191.53 234.62 777.50

2456.98 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.

This counting stick represents a scale for the range 0 to 1000g.

Q. How many grams does each division represent?

Q. What is the value of the point indicated by the red arrow.

Q. What are the values shown by the other arrows?

1000g

0g

A

B

C

Q. What value does the red arrow indicate here?

1. to the nearest division

2. exactly

Q. What values do the other arrows show?

1000g

0g

A

B

C

1000g

0g

Q. How many kg are equivalent to 1000g.

REMEMBER…

KILO means a thousand

Q. What fraction of 1kg does each division represent.

1000g

0g

Each division represents

1/10 of 1 kg.

or 0.1 of 1 kg.

If I write 0.5 kg.what does it mean?

1000g

0g

0.5 kg = ½ kg = 5/10 kg = 500g

Copy and complete this table:

0.25 kg = = =

0.75 kg = = =

0.9 kg = =

0.3 kg = =

0.6 kg = =

This counting stick now represents a scale for the range 0 to 2000g.

Q. How many grams does each division represent?

Q. What is the value of the point indicated by the red arrow.

Q. What are the values shown by the other arrows?

2000g

0g

A

B

C

Q. What value does the red arrow indicate here?

1. to the nearest division

2. exactly

Q. What values do the other arrows show?

2000g

0g

A

B

C

100g

0g

Each division now represents 10g. so the scale represents 100g.

Q. If each division changed so it became:

5g1g2g

what ranges would the scale represent?

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 kg and g g

1.25 kg 1kg 250g 1250g

1.5 kg

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 Weight in g Weight in kg

Bag of sugar 2200g 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 one-

hundredth of a kilogram in grams.

Year 5 Term 2 Unit 7

Day 4

L.O.1

To be able to convert kg to g.

0g

1 kg

Q. How many grams in 1 kg?

Q. What mass does the red arrow represent?

Q. How else can we express this mass?(3

ways)

Q. What mass is represented by each of the other arrows?

Q. How else can we express this?

A

B

C

D

0g

1 kg

Q. What mass does each of the black arrows represent?

Q. How else can we express this mass?

Q. What mass is represented by each of the green arrows?

Q. How else can we express this?

D

C

B

A

L.O.2

To be able to record estimates and readings from scales to a suitable

degree of accuracy

100g

This is a LINEAR scale

Q. What is the value of each interval?

Q. What value does each of the arrows indicate?

A B C D E

200g

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?

A B C D E

400g

Q. What is the value of each interval now?

Q. What value does each of the arrows indicate?

Q. Where does 300 g appear?

A B C D E

800g

Q. What is the value of each interval now?

Q. What value does each of the arrows indicate?

Q. Where does 500 g appear?

A B C D E

500g

Q. Where have you seen a scale like this?

Q. What is the difference between this scale and the last one?

This is a CIRCULAR scale

Q. What is the value of each interval?

Q. Which values are indicated by the arrows?

A

B

C

2 kg

Q. What is the difference between this scale and the last one?

Q. What is the value of each interval?

Q. Which values are indicated by the arrows?

A

B

C

100g

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?

This scale is much finer than the first linear one we looked at.

A B

50g

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?

A B

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 375g. 1.25 kg 0.3kg.650g 1040g 0.7kg

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 478cl 4.85l

469cl 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

200cl 400cl

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?