Perimeter; compound shapes

Success Criteria

I can understand the definition and the formula

of perimeter of more complex shapes

I can calculate the perimeter

I can show my workings

DNA Find the square root of these numbers:• 81• 64• 4• 25• 1• 36

Retrieval practice

1 HP

2 HPs

3 HPs

What is ‘y’ in 15y = 15 + 60

How many faces does a cube have?

What is the lowest common multiple of 2

and 1?

What is the product of 4 and 10?

How many lines of symmetry is in a

octagon?

What number is XXX (roman numerals)?

Retrieval practice answers

1 HP

2 HPs

3 HPs

What is ‘y’ in 15y = 15 + 60

Y = 5

How many faces does a cube have?

6

What is the lowest common multiple of 2

and 1?2

What is the product of 4 and 10?

40

How many lines of symmetry is in a

octagon?8

What number is XXX (roman numerals)?

30

Explain what mistakes people could make doing this and how we could avoid them

Daily practice

0 to 12 times table for 22…

Daily practiceExample: People could not partition properly and add incorrectly

Write the definitions for the words we will come across today – can you think of an example question for the word?

Word Definition Example

Division

Addition

Pentagon

Perimeter (Advanced)

• Let’s dive straight into it!

Let’s work out the perimeter of this shape with missing lengths

We can see that there are missing measurements.

Let us first identify what they are.

Which measurements are missing?

Work out the total perimeter for the shape

These are the missing lengths. These are the only ones parts of the shape that do not have any measurements on it.

Work out the total perimeter for the shape

• Let’s look horizontally/ landscape first. We can identify 2 lengths which are 12cm and 7cm. 12cm is the distance of the whole length and we only have part of it showing as 7cm. We can work out the rest (the missing length) by simply doing 12cm –7cm = 5cm.

Work out the total perimeter for the shape

Let’s look vertically. We can identify 2 lengths which are 8cm and 4cm. 8cm is the distance of the whole width and we only have part of it showing as 4cm. We can work out the rest (the missing width) by simply doing 8cm – 4cm = 4cm.

5cm

Work out the total perimeter for the shape

All I have to do is add up the sides: 5cm + 8cm + 12cm + 4cm + 7cm + 4cm = 40cm. This is how I work out the perimeter.

4cm

5cm

Your turn

• Draw these shapes in your books (not to scale) and work out the perimeter!

Mark your work

Your turn

• Draw these shapes in your books (not to scale) and work out the perimeter!

Mark your work

Reflection

• How do you feel about working out the perimeter when a shape has missing lengths?

• Use your red hat to express your emotions. Write 3 full sentences.

Your HOMEWORK task

Draw a shape that has 56cm as the perimeter. Label the sides with

the measurements of your choosing.

Complete this task by

answering all the

questions.

Take a picture of your

work

Send this homework task only to

year6@gordonchildrensacademy.

org.uk. Title your work Day 52

Maths

I will be able to provide feedback. I am looking for beautiful pieces of work so

that I can show them on your next lot of home learning.

Exit ticket

What went well today?

What errors did you make or avoid today?

What do you feel this lesson has made you want to learn about next?

Remember to set aside 30 minutes each day to log into TTRockstars to practice your times tables.

Be sure to keep your eye out for tournaments and battles with your classmates and us, teachers.

We look forward to challenging you!

https://ttrockstars.com/If you are unsure of your username and password, please contact the office.