To convert a number from scientific notation to standard notation, follow these steps:
1. Identify the base number and the exponent: The number given is [tex]\( 6.43 \times 10^{-4} \)[/tex]. Here, 6.43 is the base number, and [tex]\( -4 \)[/tex] is the exponent of 10.
2. Understand the meaning of the exponent: The exponent [tex]\( -4 \)[/tex] means that we need to move the decimal point 4 places to the left because it's a negative exponent. If the exponent were positive, we would move the decimal point to the right instead.
3. Move the decimal point: Starting from the base number 6.43:
- Move the decimal point one place to the left to get 0.643.
- Move the decimal point a second place to the left to get 0.0643.
- Move the decimal point a third place to the left to get 0.00643.
- Move the decimal point a fourth place to the left to get 0.000643.
4. Write down the result in standard notation: After moving the decimal point 4 places to the left, the number [tex]\( 6.43 \times 10^{-4} \)[/tex] becomes 0.000643.
So, the number [tex]\( 6.43 \times 10^{-4} \)[/tex] in standard notation is [tex]\( \boxed{0.000643} \)[/tex].
