unit 2: problem solving with mrs.campbell. our objective today is: identify factor pairs of small...
TRANSCRIPT
Unit 2: Problem Solving
withMrs.Campbell
Our objective today is:
• Identify factor pairs of small two-digit numbers
• Use factors as a strategy for mental multiplication.
Identify factor pairs
36
What do we call 36?
6x6=36
What are the factors of:
40 24 64
Use factors as a strategy for mental multiplication
4 x 3 x 5
How would you work this one out?
15 x 3 x 2
And this one?
2 x 3 x 4 x 5
Ooh, what about this?
17 X 12
Let’s look at this problem lots of ways
17 X 12
17 X 6 X 2
17 x 3 x 2 x 2 = 51 x 2 x 2 =
102 x 2 = 204.
Can you use this method to work out the following?
23 x 6 17 x 4
19 x 8
Now try these..
Day 2
• Order a set of positive and negative integers.
• Solve simple word problems.
• Begin to use brackets.
-20 0 +20
-20 0 +20
I have just spent £9. What could I have bought?
fish £2 chips £1
Fish 0 1 2 3 4Chips 9 7 5 3 1
Say a cola cost 50p and pizza £1.50. If I spend £8 what can I buy?
• In your pairs I want you to create a similar problem for other pairs to answer. You can have 10 minutes to sort something out
• We will discuss the problems and solutions.
Can you work out this puzzle
A man goes to the chip shop, and asks for “two fish and chips”. The owner asks for £6, but the man expects the total to be £5.
fish £2 chips £1
Is it ‘two (fish and chips)’
or ‘(two fish) and chips’
•2 x (£2 + £1)
• (2 x £2) + £1.
How would you work out this calculation?
6 + 3 – 2 6 – 3 + 2
What is the answer to these?
• (6 + 3) – 2 6 + (3 – 2 )
What is the answer to these?• (6 – 3) + 2 6 – (3 + 2).
How is the answer changed?
Give me a number between 20 and 50
• Roll a dice 3 times and record the numbers.
• Work with your partner to make a calculation using the 3 numbers and brackets to try and reach the target number
Here is my one!
30 is my target number I rolled the dice 3 times and got a 6,1 and a 4. These are my
calculations: (6 – 1) x 4 (6 x 4) + 1 6 x (4 + 1) (6 + 1) x 4.
Reflect
Now think about what we have been learning about.
Can you apply your learning to these questions?
Where could I place the brackets to make the largest number?
4 + 7 x 34 + 7 + 34 x 2 x 34 – 2 x 3
What about the smallest number?
Teacher Notes
• This slide show is intended to be used in close conjunction with the notes. I suggest you print off the notes and familiarise yourself with them before the lesson. Use the notes to guide you through the slides.
• Additional problems will be needed for slide 12. Add as appropriate for your children.