Page 265 - ICSE Math 6

Formula Sheet

PLAYING WITH NUMBERS
• A × B = (HCF of A and B) × (LCM of A and B)

LCM of and A B
• HCF of A and B =
A × B
HCF of and A B
• LCM of A and B =
AB×

FRACTIONS
×
b

• To convert mixed fraction a b   to improper fraction: a = (a c + ) b

 c  c c q
 x r y x
x
• To convert improper fraction  to mixed fraction: = q
y
 y y –qy
a c a c+ r
• A fraction between and =
b d b c+
a c
• > , if (a × d) > (b × c)
b d
a c
• < , if (a × d) < (b × c)
b d
a c
• = , if (a × d) = (b × c)
b d
RATIO, PROPORTION AND UNITARY METHOD

• To divide ‘a’ in the ratio x : y.
 x   y 
First part =   × a ; Second part =   × a
 x + y   x + y 
• A : B > P : Q, if (A × Q) > (B × P)
• A : B < P : Q, if (A × Q) < (B × P)
• A : B = P : Q, if (A × Q) = (B × P)

• Product of extremes = Product of means

PERCENTAGE

 x 
• x as a percentage of y =   × 100%
y
 
x × y
• x% of y =
100
• If x% of a number (say y) is z, then,
z × 100
y =
x

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