Question

how do you write 0.00643 in scientific notation? $\boldsymbol{square} \times 10^{\boldsymbol{square}}$

Explanation:

Step1: Move decimal to get 1-10

We need a number between 1 and 10, so move the decimal 4 places right: $0.00643
ightarrow 6.43$

Step2: Determine exponent sign/magnitude

Since we moved the decimal right (for a number <1), the exponent is negative, equal to the number of places moved: $-4$

Answer:

$6.43 \times 10^{-4}$
(So fill the first box with $6.43$ and the second box with $-4$)