# How do you use scientific notation to express the number 355000 to one significant figure?

Dec 29, 2016

The answer is $4 \times {10}^{5}$.

#### Explanation:

Numbers written in scientific notation have a coefficient which begins with a single non-zero digit, 1-9 inclusive. That number is then multiplied by the base 10 raised to a power (exponent). If the decimal was moved to the right, the exponent will be negative, such as $0.03 = 3 \times {10}^{- 2}$. If the decimal was moved to the left, the exponent will be positive, such as $400 = 4 \times {10}^{2}$.

The exponent indicates how to expand the number to standard notation. If it is positive, move the decimal to the right the same number of places, such as $4 \times {10}^{2} = 400$. If it is negative, move the decimal to the left the same number of places, such as $3 \times {10}^{- 2} = 0.03$.

Round $355000$ to one significant figure by rounding to $400000$. To use scientific number to express this number, move the decimal point to the left 5 places, and write the number as $4 \times {10}^{5}$.

The following website may be helpful. https://www.nyu.edu/pages/mathmol/textbook/scinot.html