Multiplication is one of the common used arithmetic operation in mathematics. Multiplication is denoted by a cross sign ×. In multiplication the order of the numbers doesn’t change the answer. So multiplication of two numbers is always commutative and associative. Multiplication can be applied to different types of numbers such as fractions, integers, decimals. Fractions are the numbers written in p/q form. A fraction number cannot have denominator equal to zero. Fractions can be changed to decimals and vice versa.
Example 1: Danny runs 0.5 miles every day. If he ran continuously for 4 days. How many miles did she cover?
Number of miles ran each day = 0.5 = 1/2.
Number of days he ran = 4.
Total number of miles Danny covered = 4 x 1/2 = 4/2.
(Here 4 and 2 have GCF 2. Divide numerator and denominator by 2.)
This gives (4 ÷ 2)/(2 ÷ 2) = 2/1 =2.
Hence Danny ran 2 miles in four days.
Question: Multiple choice question (Pick the correct option.)
What is the answer when 42 is multiplied with 0.5?
a) 24 b) 21 c) 42 d) None of these.
Explanation: Here given for the multiplication 42 x 0.5 =?
First multiply 42 with the number 5; 42 x 5 = 210.
Then multiply 42 with the number 0; 42 x 0 = 00.
Now add the two derived answers 210 + 000 = 210 and place a decimal point 21.0
Hence 42 x 0.5 = 21.