Question

What is the value of this expression (5.5) × (3.9)? Break down the calculation.

(5.5) × (3.9) equals:
a) 20.45
b) 21.45
c) 19.75
d) 22.05

Answer 1

The value of the expression (5.5) × (3.9) is calculated by multiplying 55 by 39 to get 2145 and then placing the decimal to account for the two decimal places in the original numbers, resulting in 21.45.

Step-by-step explanation:

To find the value of the expression (5.5) × (3.9), we perform the multiplication:

1. Multiply the absolute values (ignore the decimal points for now): 55 × 39.
2. The result of step 1 is 2145.
3. Count the total number of decimal places in the original numbers: 5.5 has one decimal place and 3.9 also has one, totalling two places.
4. Place the decimal point back into the result from step 1. Since we have a total of two decimal places, the answer should also have two decimal places: 21.45.

Therefore, the value of the expression (5.5) × (3.9) equals 21.45, which corresponds to option b).