This lesson contains 16 slides, with interactive quiz and text slides.
Lesson duration is: 50 min
Items in this lesson
Entry ticket
timer
6:00
Slide 1 - Slide
Entry ticket
Slide 2 - Slide
Which exercises/theories should we discuss on the board?
Slide 3 - Mind map
Today's program
Questions about the homework? §5.1 exercises S4, 4, 5 and 6
No upload in Classroom? That means: not done your HW
Refresh: Removing single brackets
New theory: Removing double brackets
Slide 4 - Slide
Removing single brackets
In §5.1 you learned how to write a formula such as y = 2t(3t + 4) without brackets, by thinking of the formula as the area of a rectangle with a side of 2t and a side of 3t + 4.
You could also work this out with a multiplication table or by drawing arcs.
Rectangle Multiplication table Arcs
Slide 5 - Slide
Draw arcs to show what multiplication you're doing.
Work this out on a peace of paper and give it to your teacher
timer
3:00
Slide 6 - Slide
Removing double brackets
In the same way, you can write formulas such as y = (2t + 3)(3t + 4) without brackets. Think of a rectangle with a side of 2t + 3 and a side of 3t + 4.
Slide 7 - Slide
Removing double brackets
What should be written in the
blue rectangle?
I don't know
5t
6t
5t2
6t2
Slide 8 - Slide
Removing double brackets
What should be written in the
green rectangle?
I don't know
6t
9t
6t2
9t2
Slide 9 - Slide
Removing double brackets
The area is
So
can be written without brackets as
Slide 10 - Slide
Removing double brackets
When removing brackets from formulas with negative numbers, you can use a multiplication table. Example: y = (2n - 7)(n + 1)
Put the 2n and -7 in the left column and n and 1 in the top row.
Slide 11 - Slide
Removing double brackets
When removing brackets from formulas with negative numbers, you can use a multiplication table. Example: y = (2n - 7)(n + 1)
Put the 2n and -7 in the left column and n and 1 in the top row.
Fill in the table.
Slide 12 - Slide
Removing double brackets
When removing brackets from formulas with negative numbers, you can use a multiplication table. Example: y = (2n - 7)(n + 1)
Put the 2n and -7 in the left column and n and 1 in the top row.
Fill in the table. Write the formula as short as possible.
Slide 13 - Slide
Removing double brackets
You can draw arcs to show what multiplications you are doing. This is sometimes called the "parrot beak" method (do you see the shape?).
Example:
Slide 14 - Slide
Which method should I use?
When being asked to write a formula without brackets, you can choose which method you use (rectangle, multiplication table, arcs, or something else).
You do not have to show how you removed the brackets, but a rectangle/table or steps will show you know how to remove brackets, even if you make small mistakes.
Slide 15 - Slide
HW Tuesday
§5.2 Do exercises 9, 11, 12 and 13b
Don't forget to check and correct your answers with the Solutions book
Lesson duration is: 50 min
