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
Lets see how
many $10 notes
there are in 200 on
the next page.
10 + 10 + 10 = 30
4 is less than
ten. So there’s
no tens here.
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 20 ten
dollar notes to make
two hundred.
We needed 3 ten
dollar notes to
make thirty.
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
Question summary: Is $324 enough money to take 31
students to a tournament which costs $10 each?
Step 1: Split 324 into hundreds, tens and ones.
Do this now on a piece of paper.
Now let’s try one together
Question summary: Is $324 enough money to take 31
students to a tournament which costs $10 each?
Step 2: Write down how many $10 notes it takes to make $20. Do
this under the 20 on your piece of paper now.
Now let’s try one together
Question summary: Is $324 enough money to take 31
students to a tournament which costs $10 each?
Step 3: Write down how many $10 notes it takes to make $300.
Do this under the 300 on your piece of paper now.
Hint: It takes ten $10 notes
to make $100.
Now let’s try one together
Question summary: Is $324 enough money to take 31
students to a tournament which costs $10 each?
Step 4: Add the two amounts together. This is the total
amount of $10 notes you have. Do this now.
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.
How many $10 notes are there in the following amounts?.
1) $246
6) $192
2) $315
7) $531
3) $185
8) $215
4) $248
9) $322
5) $356
10) $740
Only click again if you have completed all the questions
on the previous slide and you are ready to see the
answers.
1) 24
6) 19
2) 31
7) 53
3) 18
8) 21
4) 24
9) 32
5) 35
10) 74
Need some more practise? Try Pg42 of Teacher Tools Addition and
Subtraction Book Numeracy resources