Question

1. write $3.89 \cdot 10^{-5}$ in standard form.

\\(\bigcirc\\) 389,000
\\(\bigcirc\\) 0.000389
\\(\bigcirc\\) 3,890
\\(\bigcirc\\) 0.0000389

Explanation:

Step1: Recall scientific notation rule

For \( a\times10^{-n} \), we move the decimal point \( n \) places to the left. Here, \( a = 3.89 \) and \( n = 5 \).

Step2: Move decimal point

Start with \( 3.89 \). Move the decimal point 5 places to the left: \( 3.89
ightarrow0.389
ightarrow0.0389
ightarrow0.00389
ightarrow0.000389
ightarrow0.0000389 \).

Answer:

0.0000389 (the last option, which can be represented as the option with text "0.0000389")