# GCSE Mathematics Significant Figures, Powers & Roots, Decimal Places -- Units 2&3

This contains a sheet explaining the three topics separately, it then goes on to give you questions on these topics, the next pages dictates the answers in red. The last page consists of Unit 2 revision topics.

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• Created by: Charley
• Created on: 05-04-12 13:39

First 610 words of the document:

Maths Revision & Help Session
Significant Figures:
You
can us e
thi
s f
or
decimal
numb ers
and al
so whol
e numb ers.
I
f
the
fi
rst
insi
gnif
icant
number i
s a
5,
round
u p
the
last
si
gnif
ican t
number.
I
f
the
fi
rst
insi
gnif
icant
di
git
i
s a
less
than
5 you
keep t
he
last
si
gn i
fi
cant
fi
gure
the
same.
You
should
remove any
insi
gnif
icant
numbe r
s or
r
eplace t
hem w i
th
zer
os.
e.g. 1568493
rounded
to
1SF
=>
1568493
=>
2000000
R ounded
to
3SF
=>
1568493
=>
1570000
e.g. 0.
63589634
rounded
to
1SF
=>
0.63589634
=>
0.6
= 0.
60000000
(Thi
s i
sn'
t
needed)
Rounded
to
3SF
=>
0.63589634
=>
0.636
e.g. 0.
0005678391
rounded
to
1SF
=>
0.0005678391
=>
0.0006
Rounded
to
3SF
=>
0.0005678391
=>
0.000568
Decimal Places:
Thi
s can
only
be used
for
deci
ma l
numbers.
I
f
the
fi
rst
unrequi
red
numb er
i
s a
5,
round up
the
last
si
gni
fi
cant
number
.
I
f
the
fi
rst
unrequi
red
numb er
i
s a
less
than
5 you
keep t
he l
ast
si
gni
fi
cant
f
igur
e
t
he same.
You
sho ul
d r
emo ve
any numbers
that
aren'
t
needed.
e.g. 0.
678463
rounded
to
1DP
=>
0.678463
=>
0.8
Powers and Roots:
3 6
When
multiplying, yo u
h e
po wers e .
g. 5 x 5 =59
When
dividing, you subtract
t
he po wers e.g .
26
÷
2 2
=54
42
When
using brackets,
you mu l
ti
ply e.
g. (3 )
= 38
1 5
When
n i
s to t
h e
power 1 i
t
is
sti
ll
n e.
g. 7 = 7 or 3 x 3 =36
0
When
n i
s to t
h e
power 0 it
eq ual
s 1 e.
g . 6 =
1
786
When
1 i
s to n power it
equal
s 1 e.g.
1 =
1
When
app l
ied
to
fractions you
a pply
the
p o we r
to both
nume r
ator
and
denomi
nat
or
e.
g.
(1 /
3 3
5)
=
( /
8 3
5)
=
83
=
512
/125

## Other pages in this set

### Page 2

Here's a taster:

Practice Questions:
Si
gni
fi
cant
Fi
gur
es:
1)Round
to
1 SF: A)
1368 B)
0.4782 C)
67845
D )
0.0008463
E)
3.9999 F)
9568939 G)
0.039735
2)Round
to
3 SF:
A)
1368 B)
0.4782 C)
67845
D )
0.0008463
E)
3.9999 F)
9568939 G)
0.039735
Deci
mal
Pl
aces:
1)Round
to
1 DP: A)
0.054358 B)
0.3158 C)
0.65383 D )
0.
7926
E)
7.6385 F)
0.
484564 G)
3.214375
2)Round
to
2 DP: A)
0.054358 B)
0.3158 C)
0.65383 D )

Here's a taster:

Si
gni
fi
cant
Fi
gur
es:
1)Round
to
1 SF: A)
10000 B)
0.5 C)
70000
D )
0.0008
E)
4 F)
100000000G)
0.04
2)Round
to
3 SF:
A)
1370 B)
0.478 C)
67800
D )
0.0008
E)
4 F)
9570000 G)
0.0397
Deci
mal
Pl
aces:
1)Round
to
1 DP: A)
0.1 B)
0.3 C)
0.7 D)
0.8
E)
7.6 F)
0.
5 G)
3.2
2)Round
to
2 DP: A)
0.05 B)
0.32 C)
0.65 D)
0.79
E)
7.64 F)

### Page 5

Here's a taster:

Unit 2 Maths Revision Topics
NUMBER
Fact
ors and Mult
ipl
es
Pr
ime
Fa ct
ors
LCM and
H CF
Square
a nd
C ube Numb er
s
Negati
ve Numb ers
Rul
e s
of
Indices
Fr
acti
o nal
and Negati
ve I
ndices
St
an dar
d
Form
Fr
acti
o ns
Subtr
a ct
ing,
Mult
ipl
ying,
Di
vidi
ng)
Fr
acti
o ns
of
Q uanti
ti
es
Deci
ma ls
Recurr
ing Decimals
(Writ
ing