Which choice correctly expresses the number below in scientific notation?

145000

A. [tex]$1.45 \cdot 10^6$[/tex]
B. [tex]$145 \cdot 10^3$[/tex]
C. [tex]$145 \cdot 10^5$[/tex]
D. [tex]$1.45 \cdot 10^4$[/tex]
E. [tex]$1.45 \cdot 10^5$[/tex]
F. [tex]$14.5 \cdot 10^4$[/tex]

Answer :

To express the number 145,000 in scientific notation, follow these steps:

1. Understand Scientific Notation: Scientific notation represents numbers as a product of a coefficient and a power of ten. The coefficient is a number between 1 and 10 (but not equal to 10), and it is multiplied by 10 raised to an exponent.

2. Find the Coefficient: Start with the given number, 145,000. Move the decimal point in the number to create a new number between 1 and 10.

3. Move the Decimal Point: In 145,000, the decimal point is originally at the end of the number (145000.). Move it to the left to get a number between 1 and 10. That would be 1.45, by moving the decimal 5 places to the left.

4. Determine the Exponent: Count the number of places you moved the decimal point. Each move represents a power of ten. Since you moved the decimal 5 places to the left, the exponent will be 5.

5. Write in Scientific Notation: Combine the coefficient (1.45) with the power of ten (10^5). Therefore, 145,000 can be expressed in scientific notation as [tex]\(1.45 \times 10^5\)[/tex].

6. Select the Correct Choice: From the options provided, the correct expression is E. [tex]\(1.45 \cdot 10^5\)[/tex].

So, 145,000 in scientific notation is [tex]\(1.45 \times 10^5\)[/tex].