Video Transcript
Subtracting Money: Egyptian
Pounds
In this video, we’re going to learn
how to subtract within 100 to calculate the change received in pounds.
Yasmine has 20 pounds. She wants to buy these markers,
which cost 15 pounds. How could we work out how much
change she will get? We could sketch a bar model to help
us solve this problem. We know Yasmine has 20 pounds to
begin with and the markers cost 15 pounds. We have to work out how much money
she will have left. To work out the amount of change
she’ll get, we need to subtract 15 pounds from 20 pounds. What is 20 subtract 15? It’s five. So Yasmine has five pounds
left. She had 20 pounds. She spent 15 pounds. She’s got five pounds left. To help us solve the problem, we
sketched a bar model, then calculated the answer.
Let’s try some more subtraction
problems involving money by answering some questions.
Adam has 35 LE. He spends 15 LE during his day at
school. How much money does he have
left?
We know that Adam has 35
pounds. And during the course of his day at
school, he spends 15 pounds. We have to work out how much money
Adam has left. We could sketch a bar model to help
us solve the problem. We know that Adam has 35 pounds to
begin with. And he spends 15 pounds during the
day. We have to find out how much money
he’s got left.
This is a subtraction problem. We need to subtract the amount that
Adam spent from the amount he had to begin with. We need to calculate 35 take away
15. 35 take away 15 equals 20. If Adam has 35 LE and spends 15
during his day at school, he will have 20 LE or 20 pounds left. We found the answer by subtracting
15 from 35.
Amira got 20 LE from her
mother. Amira bought breakfast for 12
LE. How much money does Amira have left
after breakfast?
This is a word problem. We know that Amira had 20 pounds to
begin with. And we also know she spent 12
pounds on her breakfast. The question is asking us to work
out how much money Amira has left. We could use a part–whole model to
help us solve the problem. We know Amira had 20 pounds. And she spent 12 pounds on her
breakfast. How much money does she have
left?
One way we could solve the problem
is to subtract 12 from 20. That will tell us how much change
Amira should have. Another way we can solve the
problem is to think about which number we need to add to 12 to make 20. 12 and eight are a pair of numbers
which go together to make 20. So if 12 plus eight make 20, we
know that 20 take away 12 equals eight. So if Amira has 20 pounds and she
spends 12 pounds on her breakfast, she will have eight pounds left because 20 take
away 12 equals eight.
Sherif has the 20-pound note
shown. Sherif uses his 20-pound note to
buy a toy. The toy costs 10 pounds. What change does Sherif get?
This is a word problem. We know that Sherif has 20
pounds. And he uses his money to buy a toy
aeroplane. If the toy cost him 10 pounds, how
much change will he get? We could use a part–whole model to
help us solve the problem. We know that Sherif has 20 pounds
to begin with. And he bought a toy which cost him
10 pounds. How much money does he have
left?
One way that we could solve the
problem is to subtract 10 from 20. That will tell us how much money he
has left. Another way to solve the problem is
to think about which number we add to 10 to make 20. 10 and 10 are a pair which make
20. 20 take away 10 is 10. If Sherif has 20 pounds and he
spends 10 pounds on a toy, he will have 10 pounds left because 20 subtract 10 equals
10.
A girl had 46 pounds. She bought a dress for 34
pounds. How much does she have left?
This is a word problem. We know the girl had 46 pounds and
she spent 34 pounds on a dress. We have to calculate how much money
she has left. We can sketch a bar model to help
us think about how to solve the problem. We know the girl had 46 pounds to
begin with. And she spent 34 pounds on a
dress. So to find out how much money she
has left, we have to find the difference between 46 and 34.
We have to subtract 34 from 46. We could use the standard written
method or column subtraction to help us find the difference. 46 has six ones. 34 has four ones. We need to work out six take away
four. Six take away four is two. Now we can subtract in the tens
place. 46 has four 10s. 34 has three 10s. So we need to calculate four 10s
take away three 10s. Four take away three is one, so
we’ve got one 10 left. 46 take away 34 equals 12. If a girl has 46 pounds and she
buys a dress for 34 pounds, she will have 12 pounds left because 46 take away 34
equals 12.
What have we learned in this
video? We have learned how to calculate
the change received in pounds by subtracting.
