Calculations and Pharmaceutical Solutions Dr. Amal El-Kamel Associate professor of Pharmaceutics

Kinds of numbers In arithmetic Whole number or integer: 1, 4, 11 Fraction: 4/7, 0.25 Mixid number: 1.5, 1 3/4 Abstract or pure number: how many times the unit is repeated. It may be added or subtracted or multiplied or divided by any other abstract number. Concrete or denominate number: a number that designated a quantity of objects. It can be added to or subtracted from any other number of the same denomination. It can be multiplied or divided only by a pure number.

Important rule Number of different denomination have no numeric connection and cannot be used together. 5kg+ 10mg

Arabic numbers Any number can be expressed by numbers between 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 Any number can be expressed by numbers between 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 Ex. 5, Ex. 5, , = 5 thousands = zero hundreds = zero hundreds = 8 tens = 8 tens = 3ones = 3ones = 6 tenths = 6 tenths = 2 hundredths = 2 hundredths = 3 thousandths = 3 thousandths

Roman numbers Express the numbers by using letters. Express the numbers by using letters. SS or ss =1/2 SS or ss =1/2 I or i = 1 I or i = 1 V or v =5 V or v =5 X or x =10 X or x =10 L or l = 50 L or l = 50 C or c =100 C or c =100 D or d =500 D or d =500 M or m =1000 M or m =1000 Other numbers are expressed by combining these letters. Other numbers are expressed by combining these letters.

If two or more letters are successively equal or smaller in value the number is equal the sum of their values. Xiii13Mm2000 Mdclxvi M =1000 D=500 C= 100 L =50 X=10 V= 5 i= 1 = 1666 Two or more letters express a quantity that is the sum of the values remaining after the value of each smaller letter has been subtracted from that of the following greater. Two or more letters express a quantity that is the sum of the values remaining after the value of each smaller letter has been subtracted from that of the following greater. Iv Iv5-1=4 Vx Vx10-5=5 X i x X i x10-1=99+10=19 vii 7 Xv 15

M c m x c v = = =1995 C m x c i x =999

18Xviii126Cxxvi84Lxxxiv1989Mcmlxxxix99xcix xxxx xxxx xl xl400CcccCm4Iiiiiv 9 Viiii Ix 90 Lxxxx Xc 900 Dcccc cm