T3 Multiplication & Division Pt 2

Learning content:  uses mental and informal written strategies for multiplication and division

Learning Intention & Success Criteria

Learning intention: I am learning to solve multiplication and division problems using efficient strategies

Success criteria:

Surface:

I can recall multiplication and subtraction facts

Deep:

I can 

· Use a range of strategies to multiply and divide

· Understand that multiplication and division are the opposite of each other

· Check my answers for a problem,

· Use mathematical language in my explanations

Transfer:

I can

· Apply my knowledge of multiplication and division to solve word problems

· Explain how to solve problems

Task One

We are going to practise solving some word problems.

Problem 1

Read the problem below carefully to understand what the problem is about.

Roshi's Burgers gives away ? free drink if a family buys ? burgers.  The Turner family will buy ? burgers for a party. 

Explain what you think the number story is talking about.

Now reread it and explain what you have to find out.

Roshi's Burgers gives away ? free drink if a family buys ? burgers.  The Turner family will buy ? burgers for a party.   

How many free drinks will they receive?

Now that we know what we have to work out, let's reread the problem again - underline the important information and circle what you have to find out.

Roshi's Burgers gives away 1 free drink if a family buys 4 burgers.  The Turner family will buy 24 burgers for a party. 

How many free drinks will they receive?

Now let's work it out.  Show how you worked it out.

Problem 2

Let's go through the same process.  

First of all read the problem carefully to understand what it is about.

The supermarket is having a special promotion.  They are giving away __ free stickers with every packet of chips that they sell.  Jackson bought __ packets of chips.  

Explain what it is about.

Now reread it and explain what you have to find out.

The supermarket is having a special promotion.  They are giving away __ free stickers with every packet of chips that they sell.  Jackson bought __ packets of chips.  How many stickers will he get?

Finally, reread the problem again - underline the important information and circle what you have to find out.

Then solve it, showing how you work it out.

The supermarket is having a special promotion.  They are giving away 2 free stickers with every packet of chips that they sell.  Jackson bought 7 packets of chips.  How many stickers will he get?

Problem 3

Do this one by yourself, following the same pattern.  Make sure to show how you worked it out.

There are 25 children in Mrs Green's class.  The children sit in rows.  There are 5 children in each row.  THere are 2 boys and 3 girls in each row.  How many boys are there?  How many girls are there?

What is the connection between all of these word problems and multiplication?

Look back at each word problem and see if you can write a multiplication number sentence to match it.

Task One

Watch this video.

Have a look at the picture below.  What do you notice?  What do you wonder?

Make an estimate.  What is a number that is too low?  What is a number that is too high?  What is your estimate?

How could you convince someone that your new estimate is reasonable, without using a calculator?

Now make your own model/representations/calculations/demonstrations on whiteboards or butcher's paper.

Complete makemathmoments.com Krispy Kreme task.

Task One

Task Two

Activity One

Learning content:  We are learning about division

You teacher will follow through the makemathmoments.com Sowing seeds task with you.

If you look carefully at these sentences, you will notice that in the multiplication sentences the largest number always comes at the end, and in the division sentences the largest number always comes at the beginning.

Your teacher will now do another example using 4, 5 and 20.

Now take a look at this example:

What do you notice about it?

The bottom two number sentences don't make sense - they are division number sentences, but they don't start with the largest number.

Now it is your turn.

Use the whiteboard sleeves with three circles inside them.

Put the numbers 8 and 2 inside the two top circles, and work out what needs to go in the third circle.

Now write four number sentences using these three numbers.  Remember the biggest number goes at the end of a multiplication sentence and the biggest number goes first at the beginning of a division number sentence.

Now try one with 45 in the bottom circle and 5 in one of the top circles.  Work out what number should go in the other top circle, and then write out your four number sentences.

We can use this model to help us solve problems.

John collected 35 basketball cards to share with 7 of his friends.

How many basketball cards will each friend receive if he shares them equally?

Underline the important information and circle what you have to find out.

Now use the three circles in your whiteboard sleeve to help you work this out.

Now try another problem using the same method:

I have 30 spelling words to write out on my homework sheet.

The sheet has 3 columns.

How many words will I write in each column?

Here is another one to try:

40 people have been invited to a party.  The organiser is sorting out tables.

Each table can seat 5 people.

How many tables are needed?

Now try some questions on your own.