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Knowing Our Numbers - Coggle Diagram
Knowing Our Numbers
Roman Numerals
I = 1
V = 5
X = 10
L = 50
C = 100
D = 500
M = 1000
If a symbol is repeated, its value is added as many times it occurs.
A symbol is not repeated for more than three times. The symbols V (5), L(50) and D(500) are never repeated.
If a symbol of smaller value is written to the right of a symbol of greater value, its value gets added to the value of greater symbols.
If a symbol of smaller value is written to the left of a symbol of greater value, its value is subtracted from the value of the greater symbol.
The symbols V, L and D are never written to the left of a symbol of greater value, so they are never subtracted.
The symbol I can be subtracted from V and X only.
The Symbol X can be subtracted from L, M and C only.
Number Systems
Hindu - Arabic Numbering System
International Numbering System
There are 4 periods - Ones, Thousands, Lakhs and Crores
Ones - Ones (1), Tens (10) & Hundreds(100)
Thousands - Thousands (1000) &
Ten Thousands(10,000)
Lakhs - Lakhs(1,00,000) & Ten Lakhs(10,00,000)
Crores - Crores(1,00,00,000) & Ten Crores(10,00,00,000)
Commas are first inserted after three digits starting from the right, and then after two digits.
There are 3 periods - Ones, thousands and Millions.
Ones - Ones (1), Tens(10), Hundreds(100)
Thousands - Thousands(1000), Ten Thousands (10,000) and Hundred Thousands (100,000)
Millions- Millions (1,000,000) , Ten Millions(10,000,000) and Hundred Millions (100,000,000)
Commas are inserted after every three digits starting from the right.
The expanded form of 3,67,21,963 is- 3,00,00,000 + 60,00,000 + 7,00,000 + 20,000 + 1,000 + 900 + 60 + 3
OR
3 × 1,00,00,000 + 6 × 10,00,000 + 7 × 1,00,000 + 2 × 10,000 + 1 × 1000 + 9×100 + 6 × 10 + 3 × 1
3,67,21,963 is read as Three crore sixty-seven lakh twenty-one thousand nine hundred sixty-three.
456,784,218 is read as Four hundred fifty-six million seven hundred eighty-four thousand two hundred eighteen.
The expanded form of 456,784,218 is : 400,000,000 + 50,000,000 + 6,000,000 + 700,000 + 80,000 + 4,000 + 200 + 10 + 8
OR
4 × 100,000,000 + 5 × 10,000,000 + 6 × 1,000,000 + 7 × 100, 000 + 8 × 10,000 + 4 × 1000 + 2 × 100 + 1 × 10 + 8 × 1
Comparing Numbers
First count the number of digits in a number. The number with the greater number of digits is the bigger one.
If the number of digits is the same, then see the left most number. If it is greater than the other one, then it is greater or if equal, hop to the next digit to the right !
768, 8567, 8765, 78657, 8675, 75, 858
Greatest number is 78, 657.
The smallest one is 75.
Ascending Order
Descending Order
Eg: 123, 312, 3321, 213, 211. 3112, 2211
Ascending Order - 123, 211, 213, 312, 2211, 3112, 3321
Descending order - 3321, 3112, 2211, 312, 213, 211 , 123
9 + 1 = 10
99 + 1 = 100
999 + 1 = 1,000
9,999 + 1 = 10,000
99,999 + 1 = 1,00,000
9,99,999 + 1 = 10,00,000
99,99,999 + 1 = 1,00,00,000
1 Lakh = 10 Ten Thousand
1 Million = 10 Hundred Thousands
1 Crore = 10 Ten Lakh
1 Crore = 10 Million
1 Million = 10 Lakh
Estimating is very much useful in doing various maths sum of various types.
Estimating means to round off any number to its nearest 10s, 100s or 1000s.
There are no rigid rules when we want to estimate the outcomes of numbers.
We use brackets to simplify our work so that we can solve it easily.
Eg : 7 x 109 = 7 x (100+9)
= 7 x 100 + 7 x 9
= 700 + 63
= 763