FOUR BASIC ARITHMETIC OPERATIONS
Review of Introductory Mathematics
The associative law for multiplication permitted multiplication of factors in any order. In
division, this is not allowed.
(a÷b) ÷ c a ÷ (b÷c)
Example:
(8÷4) ÷ 2 8 ÷ (4÷2)
1 4
When dividing two numbers, the divisor and dividend are lined up horizontally with the divisor
to the left of the dividend. Division starts from the left of the dividend and the quotient is
written on a line above the dividend.
Example 1:
Divide 347 by 5.
Solution:
Starting from the left of the dividend, the divisor is divided into the first digit or set of
digits it divides into. In this case, 5 is divided into 34; the result is 6, which is placed
above the 4.
This result (6) is then multiplied by the divisor, and the product is subtracted from the
set of digits in the dividend first selected. 6 x 5 equals 30; 30 subtracted from 34 equals
4.
The next digit to the right in the dividend is then brought down, and the divisor is divided
into this number. In this case, the 7 is brought down, and 5 is divided into 47; the result
is 9, which is placed above the 7.
Again, this result is multiplied by the divisor, and the product is subtracted from the last
number used for division. 9 x 5 equals 45; 45 subtracted from 47 equals 2. This process
is repeated until all of the digits in the dividend have been brought down. In this case,
there are no more digits in the dividend. The result of the last subtraction is the
remainder. The number placed above the dividend is the quotient. In this case, 347 ÷
5 yields a quotient of 69 with a remainder of 2.
MA-01
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