Chapter 03 - the Visible Pc

id you remember to explain your calculation in words, and to write in sentences? And did you remember to use the unrounded value 1714 from part (a), not the rounded value 1710? If you used the rounded value, then you will have obtained the answer 51%, which is not the answer given in the question. Activity 34
See how many of the following possible improvements you spotted – but don’t worry if you didn’t spot them all! The author of the solution could: • explain the calculations in words and write in sentences • include a conclusion for each question part, stating the answer clearly in the context of the question • include the units in part (a)
• round the answer to part (a) to three significant figures, as requested in the question
• check the answer to part (b) against the given answer of 52%, and try to find the mistake
• correct the mistake – the amount of paper recycled five years ago was 1130 tonnes, not
1714 tonnes, so the increase as a fraction of the
584 584 amount five years ago is ,not
1130 1714
• write .34 as 0.34 – a decimal point should have a digit on each side to make it easy to read – it’s easy to mistake .34 for 34
• write 0.34 as the percentage 34%, since the question referred to the percentage rise
• use equals signs correctly – see the text following the activity.
Activity 35
The equals sign in
584
584 =
1714
is used incorrectly. The fraction on the right-hand side is not equal to 584.
The equals sign in
584
= .34
1714
is also used incorrectly. The fraction on the left is not exactly equal to 0.34, so the author of the solution should have either used the approximately equals sign or included the rounding precision.
That is, he or she should have written either