1. Lakes and Reservoirs of Wales http://attractions.walesdirectory.co.uk/Lakes_and_Reservoirs.htm

2. Lakes and Reservoirs of Wales – the cards Lake Vyrnwy

3. You will probably need the following information to convert between units of measure: 1 m 3 = 219.97 Imperial Gallons 1 Acre = 4,046.86 m 2 1 hectare = 10,000 m 2 1 km 2 = 1,000,000 m 2

4. Reservoir Trumps 1.Divide the cards equally between the 2 or 3 players. 2.Decide on which category you will compare the cards – either surface area or water volume. 3.As you play the cards, you will have to compare the amounts shown. Note that different units of measurement are often used, as well as standard form. 4.The winner is the one who has most cards at the end of a run. 5.Repeat the game for the other category.

5. Ordering and correlation 1.Order the cards by surface area from largest to smallest. 2.Now look at the cards and check whether they remain in order if you compare them by volume. 3.How many cards do you have to move? 4.Why might a reservoir with a larger surface area have a smaller volume? 5.Is there a correlation between the volume and the surface area of the lakes? How would you find out?

6. How many times? How many of the smallest reservoir would divide into the largest by volume, by surface area? Make similar comparisons with other pairs of reservoirs.

7. How much bigger? Choose any two cards. Find the differences between the surface areas and the volumes. Express your answers in standard form. Repeat for other pairs of cards.

8. 1. Llyn Trawsfynydd and Nant y Moch have volumes of 33190000m 3 and 32564000m 3 respectively. However, when these figures are rounded to two significant figures, what do you notice? 2. Is the same degree of accuracy given for the information in all of the cards? Upper and lower bounds

9. * Answers

10. When organised in order of surface area:

11. When organised in order of volume: Note: The calculations are based on the rounded figures given in the card sets.