OPERATIONS ON NUMBERS

SECTION-1: 

1.       NUMBERS:  in Hindu- Arabic system, we have ten digits, namely 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, called zero, one two, three, four, five, six, seven, eight and nine respectively.

 A number is denoted by a group of digits, called numeral.

For denoting a numeral, we use the place-value chart, given below,

EX. 1.  Write each of the following numberless in words.

SOL.  The given numerals in words are.

                     I.            Six lac thirty-eight thousand five dared fort-nine.

                   II.            Twenty-three lac eighty thousand nine hundred seventeen.

                 III.            Eight crore fifty-four lac sixteen thousand eight.

                 IV.            Fifty-six crore thirteen lac seven thousand ninety.

    EX.2. write each of the following numbers in figures.

                 I.            Nine crore four lac six thousand two

               II.            Twelve crore seven lac nine thousand two hundred seven.

             III.            Four lac four thousand forty.

             IV.            Twenty-one crore sixty lac five thousand fourteen.

Sol. using the place value chart, we may write.

2.        2. Face  value and place value (or local value) of a digit in a numeral

(I)                 The face value of a digit in a numeral is its own value, at whatever place it may be 

 EX. In the numeral   6872, the face value of 2 is 2, the face value of 7, the face value of 8 is 8 and the face value of 6 is 6.

(II)               In a given numeral:

Place value of unit digit=(unit digit) x 1,

Place value of tens digit = (tens digit) x 10,

Place value of hundred’s digit = (hundred’s digit) x 100 and so on.

Ex. In the numeral 70984, we have

Place value of 4= (4x1) =4

Place value of 8 = (8 x 10) =80.

Place value of  9 = (9 x 100 )= 900,

Place value of 7 = (7 x 10000) =70000.