Cambridge International Mathematics

12 Assumed Knowledge (Number)

Remember that although you may perform operations on fractions using your calculator, youmust not rely

on your calculator and forget how to manually perform operations with fractions.

Example 17 Self Tutor

Find, using your calculator: a^14 ¡^23 b 1121 +2^14 c^14 ¥^23

Note the solution given is for a scientific calculator or theCasio fx-9860G.

a^14 ¡^23 Key in 1 ab/c 4 ¡ 2 ab/c 3 EXE

Display Answer: ¡ 125

b 1121 +2^14 Key in 1 ab/c 1 ab/c 12 + 2 ab/c 1 ab/c 4 EXE SHIFT FJID

Display Answer: (^313)
c^14 ¥^23 Key in 1 ab/c 4 ¥ 2 ab/c 3 EXE
Display Answer:^38
7 Find, using your calculator:
a^15 +^13 b^13 +^27 c^58 ¡^27 d^34 ¡^13
e^25 £^32 f^47 £^23 g^67 £^25 h^35 ¥^29
i 214 +2^12 £^34 j 137 £ 218 +1^17 k 237 ¥(2^34 £^47 )
Rather than writing 3 £ 3 £ 3 £ 3 , we can write such a product as 34.
We call this power orindex notation.
34 reads “three to the power of four” or “three to the fourth”.
Since 22 =4, we write
p
4=2where
p
4 reads “the square root
of 4 ”.
Also, since 23 =8we write^3
p
8=2where^3
p
8 reads “the
cube root of 8 ”.
In general, if an=b then n
p
b=a.
For example, 27 = 128 so^7
p
128 = 2.
E POWERS AND ROOTS [1.4]
3
4
power,
index or
exponent
base
IGCSE01
cyan magenta yellow black
(^05255075950525507595)
100 100
(^05255075950525507595)
100 100
Y:\HAESE\IGCSE01\IG01_AS\012IGCSE01_AS.CDR Wednesday, 10 September 2008 2:11:28 PM PETER
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