Ratio of a Circle's Circumference to its Diameter (pi)
π
3.14159265
22/7
Base for Natural (Naperian) Logarithms
e
2.71828183
Golden Ratio (derived from Fibonacci series)
1.61803399
Square root of Two
√2
1.41421356
99/70
Square root of Three
√3
1.73205081
Square root of Ten
√10
3.16227766
Cube root of Ten
3√10
2.15443469
Number Size Prefixes
Defined by the SI Metric International System of Units
Increasing
Prefix
Symbol
Factor
deca
da
10
hecto
h
102
kilo
k
103
mega
M
106
giga
G
109
tera
T
1012
peta
P
1015
exa
E
1018
zetta
Z
1021
yotta
Y
1024
Decreasing
Prefix
Symbol
Factor
deci
d
10-1
centi
c
10-2
milli
m
10-3
micro
µ
10-6
nano
n
10-9
pico
p
10-12
femto
f
10-15
atto
a
10-18
zepto
z
10-21
yocto
y
10-24
Numerical Approximations
Area
A doubles tennis court measures 78 ft long by 36 ft wide.
The playing area is 2808 ft² (312 yd²).
1 acre is equivalent to approx 15½ doubles tennis courts
1 hectare is equivalent to approx 38⅓ doubles tennis courts
There is no single size for a football (soccer) pitch.
Rules simply state that it must be 100-130 yards long and 50-100 yards wide.
Manchester City has one of the largest at 116x77 yds.
The playing area is 8932 yd² (1.85 acres).
Before moving to the Olympic stadium, West Ham had one of the smallest at 110x70 yds.
The playing area was 7700 yd² (1.59 acres).
Assuming the average size soccer pitch size to be 112x72 yds,
then the playing area is 8064 yd² (1.67 or 1⅔ acres).
1 acre is equivalent to 0.6 (approx ⅔) average soccer pitch
1 hectare is equivalent to 1.48 (approx 1½) average soccer pitches
