Answer:
4 x 10^2
Step-by-step explanation:
Step 1
To find a, take the number and move a decimal place to the right one position.
Original Number: 400
Step 2
Now, to find the scientific notation, count how many places to the right of the decimal.
There are 2 places to the right of the decimal place.
Step 3
Building upon what we know above, we can now reconstruct the number into scientific notation.
Remember, the notation is: a x 10^b
a = 4 (Please notice any zeroes on the end have been removed)
b = 2
Now the whole thing:
4 x 10^2
Step 4
Check your work:
4 x 10^2 = 4 x 100 = 400