Solve it...!

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.

• 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?

• 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?

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?

 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

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.

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?

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?

These problems were sourced by
North East Lincolnshire's Numeracy Team

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