04.05.2020

WALT: solve addition and subtraction word problems

YOU DO NOT NEED TO SUBMIT TODAY’S WORK

This week you will be learning to solve addition and subtraction word problems. You will need to read the word problems carefully so that you know whether you need to add or subtract.

This is a word problem:Emily has 15 gel pens. Coral has 28 gel pens. How many

more gel pens does Coral have compared to Emily?

When you add, your number gets….BIGGER! When you subtract, your number gets…?

Have a look at the vocabulary below. These are all the different ways you might be told to add.

Here is the vocabulary for subtraction.

But be careful! You do need to

understand the word problem to see what it is asking for. You cannot just look for the vocabulary and assume it is either addition or subtraction. Sometimes word problems use the word ‘altogether’ to ask a question. Sometimes word problems ask for ‘how many more?’ which is not always addition, sometimes it’s finding the difference, which is subtraction. So be careful!

Have a look at this poster. It will help you to solve word problems.

Let’s practise!

There are 25 marbles in a jar. I take 11 out. How many marbles are left in the jar?

Tip 1: Read the question Tip 2: Understand the question

Tip 3: Start writing it out as a number sentence whilst you are reading it.

There are 25 marbles in a jar.

25 I take 11 out.

25 - 11

Answer: 25 – 11 = 14. There were 14 marbles left in the jar.

Example 2

I have 30 rubber ducks. Dad gives me 15 more. How many rubber ducks do I have now?

I have 30 rubber ducks. Dad gives me 15 more. How many rubber ducks do I have now?

30 + 15

I read the word problem, sentence by sentence.

I started writing out the first key number.

Then I found the vocabulary to tell me which operation to use.

Then I read the next sentence to see which other numbers I had to use.

Here we know Dad is adding to the amount of ducks I already have, so it means our number will get bigger.

Answer: 30 + 15 = 45. I now have 45 ducks.

Example 3:

This is one to be careful of. Sometimes we are comparing two numbers. When we compare, we are finding the difference, which means we need to subtract or count on.

Daniel has 13 marbles. Ella has 27 marbles. How many more marbles does Ella have? Here we know Ella has the more marbles compared to Daniel, but we want to find out how much more she has.

So we can either find the difference 27 – 13 or count on from 13 to 27Answer: 27 – 13 = 14. Ella has 14 more marbles than Daniel.

Your Activity

YOU DO NOT NEED TO SUBMIT TODAY’S WORKYou only need to do up to question 5:

https://www.mathplayground.com/GrandSlamMath1.html

https://www.mathplayground.com/wpdatabase/05c.html

If you do not have flash player you can do this instead: