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1 of 5
Higher
Calculator
R9 Percentages
Question 1 · 4 marks
Spec and skills
Paper scope: Papers 2/3: calculator practice
Spec R9
Spec N12
Original practice question
Answer and supported method checks
The number of birds on an island increases by
20
%
20\%
20%
one year and then decreases by
20
%
20\%
20%
the next year.
(a)
Show that the overall change over the two years is a decrease of
4
%
4\%
4%
.
2 marks
Put the argument in order.
1
Tap a step below
2
0.96
0.96
0.96
is
96
%
96\%
96%
of the original, so the overall change is a decrease of
4
%
4\%
4%
(a change of
−
4
%
-4\%
−
4%
).
Multiply the multipliers.
1.2
×
0.8
=
0.96
1.2 \times 0.8 = 0.96
1.2
×
0.8
=
0.96