How many ten-dollar notes

I am learning how many tens there are in numbers less than 1000.

SAMPLE PROBLEM

A sports club has $234 to spend on trophies for their prize giving. The trophies cost $10 each to buy. Can they buy 23 trophies for their prize giving?

SAMPLE PROBLEM

Step 1: First we must break up 234 into its parts.

200 + 30 + 4 = 234

SAMPLE PROBLEM

Step 2: Now we must work out how many tens there are.

200 + 30 + 4 = 234

4 is less than ten. So there’s no tens here.10 + 10 + 10 = 30

Lets see how many $10 notes there are in 200 on the next page.

SAMPLE PROBLEM

Step 3: We need to work out how many ten dollar notes there are in 200.

100 + 100 = 200

That’s ten $10 notes over here

and ten $10 notes over here

That means $200 is made up of twenty $10 notes

SAMPLE PROBLEM

Step 4: Now we need to work out how may ten dollar notes that is in total.

234

We needed 3 ten dollar notes to make thirty.

We needed 20 ten dollar notes to make two hundred.

That means we needed 23 ten dollar notes in total.20 + 3 = 23

SAMPLE PROBLEM

Answer: Yes, they have enough money to buy the 23 trophies they need. In fact they will have $4 left over.

Now let’s try one together

Hillcrest School are going to a sports tournament in town. They have $324 to pay for the students to go. It costs $10 per person to enter the tournament and they are taking 31 students. Do they have enough money?

Question summary: Is $324 enough money to take 31 students to a tournament which costs $10 each?

Now let’s try one together

Step 1: Split 324 into hundreds, tens and ones. Do this now on a piece of paper.

Question summary: Is $324 enough money to take 31 students to a tournament which costs $10 each?

Now let’s try one together

Step 2: Write down how many $10 notes it takes to make $20. Do this under the 20 on your piece of paper now.

Question summary: Is $324 enough money to take 31 students to a tournament which costs $10 each?

Now let’s try one together

Step 3: Write down how many $10 notes it takes to make $300. Do this under the 300 on your piece of paper now.

Question summary: Is $324 enough money to take 31 students to a tournament which costs $10 each?

Hint: It takes ten $10 notes to make $100.

Now let’s try one together

Step 4: Add the two amounts together. This is the total amount of $10 notes you have. Do this now.

Question summary: Is $324 enough money to take 31 students to a tournament which costs $10 each?

Answer: We needed thirty one $10 notes to take everyone to the tournament and we have thirty two $10 notes. That means everyone can go.

In fact we could actually take one more person.

Now try these questions on your own.

1) $246

2) $315

3) $185

4) $248

5) $356

6) $192

7) $531

8) $215

9) $322

10) $740

How many $10 notes are there in the following amounts?.

Only click again if you have completed all the questions on the previous slide and you are

ready to see the answers.1) 24

2) 31

3) 18

4) 24

5) 35

6) 19

7) 53

8) 21

9) 32

10) 74

Need some more practise? Try Pg42 of Teacher Tools Addition and Subtraction Book Numeracy resources