Numeracy problems
to solve for Key Stage 1, 2 and 3
Key
Stage 1 Solve it...!
Do you waste or help save water

Do you leave the tap running
when you wash your hands or clean your teeth?
Does this mean you are wasting
water?
Try these activities and
find out.
You may need an adult to help you.
Task A: Washing your hands.
 Put a washing up bowl
in your sink, or put the plug in.
 Wash your hands with soap
and cold water with the tap running.
 Make a mark where the
level of water is when you've finished.
 Empty the water.
 Now wash your hands again
but turn the tap off whilst you are using the soap to clean your hands.
 Make a mark where the
level of the water is now.
Did you save water by not
having the tap running all the time?
Task B: Cleaning your teeth.
 Put a washing up bowl
in your sink.
 Turn the tap on and leave
it running all the time you are cleaning your teeth.
 Use a measuring jug to
see how much water has been used.
 Now do the same thing
again but turn the tap off whilst you are actually brushing your teeth.
 How much water have you
used this time?
Finish these sentences
I saved _______ water
when I brushed my teeth without leaving the tap on all the time.
I brush my teeth _______ times a day.
In a day I could save _______ water.
In a week I could save _______
water.
Key
Stage 2 Solve it...!
Down the drain! 
We all use a lot of water,
yet much of it goes down the drain. How can we save water?
Task A: Shower Time
Shower or bath? Which is best?
The average shower uses about
15 litres a minute. Finish the table.
Time
in shower

Water
used

30
seconds


1
minute

15
litres

2.5
minutes


3
minutes


If an average bath uses about
2 1/2 times more water than a 3 minute shower, how many litres is this?
Assuming you took a bath daily, how much water could be saved in a week
if you showered each day instead?
Task B: How efficient is
your shower?
AT HOME
Hold
a bucket under your shower for 15 seconds. Measure the amount
of water. Multiply by 4.
Have you got an efficient
shower?


Check
9
litres or less per minute = excellent
9  12 litres/minute = high efficiency
12 plus litres/minute = poor

Cleaning Your
Teeth
Leaving the tap running while you clean your teeth can waste 5 litres
of water. Assuming you and your family clean your teeth twice a day,
how many litres would be saved if you each turned the tap off while
brushing?
time

water
saved

a
day


a
week


a
year


Dripping tap
Fact: Did you know that 10 drips per minute from a leaking tap
wastes 3000 litres of water a year?
At the rate of 10 drips per
minute, how many litres of water are wasted a day?
Complete the table below.
DRIPS
PER MINUTE

LITRES
WASTED

5

day

week

year

10



3000

20




30




Is there a tap in your house
that drips (If not , turn one that drips slowly . Don't forget to turn
it off when you have finished.)
How long does it take to waste 10 milliltres of water?
How long would it take to waste a litre of water? (time)
How many drips per minute is your tap dripping?
How
much water would this tap waste?

an
hour

a
day

a
week

a
year

.




Key
Stage 3 Solve it...!
Water waste 
Water is a precious resource.
Much of it is needed to keep houses supplied. Unfortunately, much of
it goes down the drain.
Cleaning your teeth
Do you leave the tap running
when brushing your teeth? It is recommended that brushing should last
2 minutes. how much water is wasted during this time?
Measure how much water you waste in 30 seconds. How much water would
be wasted in 2 minutes.
How much would your family waste in a week, a year, (assuming everyone
brushes their teeth twice a day).
Shower Time
The average shower uses about 15 litres a minute. Finish the table.
time
in shower

water
used

30
seconds


1
minute

15
litres

2.5
minutes


3
minutes


1. An average bath uses about
2 1/2 times more water than a 3 minute shower. How many litres is this?
2. Assuming you took a bath
daily, how much water could be saved in a week if you showered each
day instead?
Fact: Did you know
that 10 drips per minute from a leaking tap wastes 3000 litres of water
a year? At this rate, how much water in wasted each day?
Complete the table below
DRIPS
PER MINUTE

LITRES
WASTED


day

week

year

10



3000

20




30




How long would it take to
lose 6000 litres of water at a rate of 5 drips per minute?
An extra task
find a tap that is dripping. How long does it take to collect 10 millilitres
of water?
How long would it take to waste a litre of water?
