Number Systems


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Each of the following are representations of the same number

0.012 =3250 =1.2⁢% =1.2×10-2 = 0.000000112

(Decimals, Fractions, Percentages, Standard Form, Binary)

They are, however, presented in different forms. Each form will be more useful in one or more situations

Common decimal, percentages and fractions compared


other systems

Roman Numerals

Cuneiform Numbers


Decimals

Decimal Addition Video:
Practice Questions;
Textbook Exercise.
Decimal Subtraction Video:
Practice Questions;
Textbook Exercise.
Decimal division by decimals Video:
Practice Questions;
Textbook Exercise.
Dividing decimals by integers Video:
Practice Questions;
Textbook Exercise.
Multiplying Decimals Video:
Practice Questions;
Textbook Exercise.
Ordering Decimals Video:
Practice Questions;
Textbook Exercise.
Division: by decimals Video:
Practice Questions;
Textbook Exercise.
Division: decimals by integers Video:
Practice Questions;
Textbook Exercise.
Multiplication: decimals Video:
Practice Questions;
Textbook Exercise.

Recurring Decimal

Decimals: recurring decimals Video:
Practice Questions;
Textbook Exercise.
(Care of corbettmaths.com)
Recurring Decimals to Fractions
Exam Questions
Converting Recurring Decimals to Fractions
Solutions
(Care of www.mathsgenie.co.uk)

Fractions

A fraction has been simplified when the numerator and the denominator have no common factor greater than one.

2842 =2×143×14 =23 4.510.5=45105 =3×157×15 =37

Remember

325=12100=0.12 7 20 = 7×100% 20 = 7×5% = 35%
FDP: percentages to fractions Video:
Practice Questions;
Textbook Exercise.
FDP: decimals to fractions Video:
Practice Questions;
Textbook Exercise
Decimals to Fractions (calc) Video:
Practice Questions;
Textbook Exercise.
Fractions to Percentages Video:
Practice Questions;
Textbook Exercise.
Fractions to Decimals Video:
Practice Questions;
Textbook Exercise.
Fractions to Decimals (calc) Video:
Practice Questions;
Textbook Exercise.
Fractions: addition same denominator Video:
Practice Questions
Textbook Exercise
Fractions: addition different denominators Video:
Practice Questions;
Textbook Exercise
Fractions: equivalent Video:
Practice Questions;
Textbook Exercise.
Expressing as Fraction Video:
Practice Questions;
Textbook Exercise.
Fractions: fraction of an amount Video:
Practice Questions;
Textbook Exercise.
Finding the original fraction Video:
Practice Questions;
Textbook Exercise
Fractions: improper to mixed number Video:
Practice Questions;
Textbook Exercise
Fractions: mixed number to improper Video:
Practice Questions;
Textbook Exercise
Fractions: increasing by a fraction Video 141:
Practice Questions;
Textbook Exercise.
Fractions: finding the midpoint Video:
Practice Questions.
Fractions: of shapes Video:
Practice Questions;
Textbook Exercise.
Fractions: ordering Video:
Practice Questions;
Textbook Exercise.
Fractions: reciprocal Video:
Practice Questions;
Textbook Exercise
Fractions: simplifying Video:
Practice Questions;
Textbook Exercise.

Fractions: Multipling and Dividing

Percentages

Percentages: compound interest Video:
Practice Questions;
Textbook Exercise.
Percentages: simple interest Video:
Practice Questions.
Expressing One Quantity as a Percentage of Another Video :
Practice Questions;
Textbook Exercise.
Percentages: increasing\decreasing Video:
Practice Questions;
Textbook Exercise.
Percentages: multipliers Video:
Practice Questions;
Textbook Exercise.

Percentages: reverse Video 240 Practice Questions Textbook Exercise

FDP: percentages to decimals Video 121 Practice Questions Textbook Exercise

FDP: percentages to fractions Video 122 Practice Questions Textbook Exercise

Decimals to percentages Video:
Practice Questions;
Textbook Exercise.
Fractions to percentages Video:
Practice Questions;
Textbook Exercise.

FDP: mixture Video 130 Practice Questions Textbook Exercise

FDP: ordering Video:
Practice Questions;
Textbook Exercise.
percentages to decimals
Practice Questions
Textbook Exercise
percentages to fractions
Practice Questions
Textbook Exercise
decimals to percentages
Practice Questions
Textbook Exercise
fractions to percentages
Practice Questions
Textbook Exercise
Percentage change
Practice Questions
Textbook Exercise
Percentage of an amount (non-calc)
Practice Questions
Textbook Exercise
Percentage of an amount (calc)
Practice Questions
Textbook Exercise
Expressing as a percentage
Practice Questions
Textbook Exercise
Increasing\decreasing by a percentage
Practice Questions
Textbook Exercise
Multiplier for percentage increase/decrease
Practice Questions
Textbook Exercise
Reverse percentages

You can use reverse percentages to find the original amount after a percentage increase of decrease.

Example:
In a year, the value of a push bicycle dropped by 15⁢% to £1125.
How much was the bicycle worth a year ago?

100⁢%-15⁢%=85⁢%or0.85

So, using function machines, original price→×0.85 →1125

Therefore, 1125→÷0.85→1500

The bike was worth £1500 a year ago.

Practice Questions [MS];
Textbook Exercise

See also Interest


Standard Form

A×10n

Videos and Questions:

Standard Form Video:
Practice Questions;
Textbook Exercise.
Standard Form: Addition Video:
Practice Questions:
Textbook Exercise.
Standard Form: Multiplication Video:
Practice Questions;
Textbook Exercise.
Standard Form: Division Video;
Practice Questions;
Textbook Exercise.
(Care of corbettmaths.com)
Standard Form Worksheet.
(Care of www.physicsandmathstutor.com)
Standard Form:
Exam Questions;
Standard Form [ MS ].
(Care of www.mathsgenie.co.uk)

Binary

Like decimal each column of a binary number is a multiply of a power of base, but the base is two not ten. Again like decimal binary has as many digit types as its base, i.e., 0 and 1.

2524 2322 2120
32168 421

So, 101111 in binary represents

25+23+22 +21+20 =32+8+4+2+1 =47

in decimal

i.e., 1011112=4710

DecimalBinarySum of powers of two
 000000 0+0+0+0+0
 100001 0+0+0+0+1
 200010 0+0+0+2+0
 300011 0+0+0+2+1
 400100 0+0+4+0+0
 500101 0+0+4+0+1
 600110 0+0+4+2+0
 700111 0+0+4+2+1
 801000 0+8+0+0+0
 901001 0+8+0+0+1
1001010 0+8+0+2+0
1101011 0+8+0+2+1
1201100 0+8+4+0+0
1301101 0+8+4+0+1
1401110 0+8+4+2+0
1501111 0+8+4+2+1
161000016+0+0+0+0
171000116+0+0+0+1
181001016+0+0+2+0
191001116+0+0+2+1
201010016+0+4+0+0
211010116+0+4+0+1
221011016+0+4+2+0
231011116+0+4+2+1
241100016+8+0+0+0
251100116+8+0+0+1
261101016+8+0+2+0
271101116+8+0+2+1
281110016+8+4+0+0
291110116+8+4+0+1
301111016+8+4+2+0
311111116+8+4+2+1

See also:

Binary Numbers

Binary Basics


Questions:

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Roman Numerals.

Roman Numerals are written with combinations of seven letters from the Latin alphabet, each letter with a fixed positive whole number value:

IVXLCDM
1510501005001000

By collecting combinations, largest value left-most and smallest right-most, numbers can be formed:

Decimal
Number
Roman
Numeral
1I
2II
3III
4IIII
(IV)
5V
6VI
7VII
8VIII
9VIIII
(IX)
10X
11XI
12XII
13XIII
14XIIII
(XIV)
15XV
16XVI
17XVII
18XVIII
19XVIIII
(XIX)
20XX
30XXX
40XXXX
(XL)
50L


Decimal
Number
Roman
Numeral
60LX
70LXX
80LXXX
90LXXXX
(XC)
99LXXXXVIIII
(XCIX)
100C
110CX
200CC
300CCC
400CCCC
(CD)
500D
600DC
700DCC
800DCCC
900DCCCC
(CM)
999DCCCCLXXXXVIIII
(CMXCIX)
1000M
1331MCCCXXXI
1967MDCCCCLXVII
(MCMLXVII)
1999 MDCCCCLXXXXVIIII
(MCMXCIX)
2006 MMVI
2024 MMXXIIII
(MMXXIV)

Ref: en.wikipedia.org/wiki/Roman_numerals


Videos and Questions:

Roman Numerals Video:
Questions [ MS ].
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