STRAND: Number
TOPIC:
Decimal numbers
Palindromes
A palindrome is something that reads the same both forwards and backwards. For example, MUM is a palindromic word as it
remains unchanged when spelt backwards. The phrase: A MAN A PLAN A CANAL PANAMA is also palindromic.
LITERACY TASK • Find the meanings of these key terms:
1. List five 3-letter words that are palindromic: ................................................................................................................
2. List five 4-letter words that are palindromic: ................................................................................................................
3. Can you find a 6-letter palindrome?:..............................................................................................................................
4. There is a suburb in Adelaide that
has 7 letters. This word is the longest
palindrome in the English language.
Can you find this word?:
Willaston
Two Wells
ay
hw
efield
Road
Outer
Harbor
2. Add the reverse number. In this case, 361.
163 +
361
North
Haven
Elizabeth
Salisbury
North
Elizabeth Vale
Para
Salisbury
Taperoo
South Para
Reservoir
rt
RAAF
Base
e
Torrens
Island
Blakeview
Stu
Wak
GULF
ST VINCENT
Barossa
Reservoir
Williamstown
tl
Lit
Little Para
Reservoir
Salisbury Heights
Parafield Brahma Lodge Fairview
Para Hills
Park
Pooraka
Cavan
Tea Tree
Para Vista
Gully
Modbury
Gepps Cross
Riv
Kersbrook
er
Millbrook
Reservoir
nge
Port Adelaide
Semaphore
Hope Valley
Highbury Torrens
Kilburn
Kangaroo Creek
Reservoir
Reservoir
West Lakes Cheltenham
Enfield
Campbelltown
Woodville
r
e
Tennyson
v
Prospect Ri
Payneham
Lobethal
Findon
Grange
North Adelaide
Kensington
Henley Beach
Thebarton
Norwood Gardens
City
West Beach
Richmond
Burnside
Adelaide
Glenside
Ashford Unley
Woodside
Airport
Pr
Black Highgate
inc
Mt Lofty
es
Forest
727 m
Edwardstown Mitcham
Glenelg
High
way
Glengowrie
Crafers
St Marys
Balhannah
Stirling
Marion
Bridgewater
Urban area
Blackwood
Aldgate
Brighton
Hahndorf
Sturt
Industrial area
Coromandel
Littlehampton
Valley
Parkland or
s
Port
Smithfield
Hig
Munno Para
Virginia
Now let’s examine some palindromic numbers. For
example, 1331 is a palindrome. We are actually able
to generate palindromic numbers using addition.
Lof
ty
Ra
3. Is the result a palindrome? If not, use this result
and repeat step 2 until a palindrome is formed.
You should have a palindrome after this step.
(The answer is 949).
t
Stur
5. Find a number that will take three additions to
form a palindrome.
Mo
unt
4. Find a number that will form a palindrome after
only one addition.
Rive
r
Palindromic decimal numbers:
A palindromic decimal number reads exactly the
same from left to right. For example, 75.57 is a
palindromic decimal number but 6.96 is not because
of the decimal point’s location. We are now going
to find out if the same method used above can be
used to generate palindromic decimals.
River
ler
Gaw
Palindromic numbers:
1. Start with a non-palindromic number. In this
case, we will use 163.
Lyndoch
Gawler
Evanston
forest reserve
Eden Hills
Sheidow
Happy Valley
Park ver
Reservoir
i
R Happy
Field
Valley
Reynella
ga
Lonsdale
rin
pa
ka
Morphett Vale
n
O
Christies Beach
Hallett Cove
N
er
Riv
Mount Bold
Reservoir
0
Mount Barker
Echunga
4
8 km
1. Add 7.2 to its reverse. Is a palindromic decimal number formed?
2. Add 5.6 to its reverse. Is a palindromic decimal number formed? If not, perform the next addition.
3. How many steps are needed to form a palindromic decimal number beginning with 6.8?
4. How many steps does it take to form a palindromic decimal number beginning with 3.65? Do you notice any numbers
during your calculations that would be palindromes if it wasn’t for the decimal point?
5. Investigate other decimal numbers to see if this method will always work for decimal numbers as well as whole numbers.
 John Wiley & Sons Australia, Ltd 2001