I really DON'T get this?

Question

Charlie lost the 200 meter race by 1/100 of a second

Describe this as a power of ten with a negative exponent

Answer 1

10 ^ -2 = 1/(10 ^ 2) = 1/100

Answer 2

1/100 of a second can be expressed as a decimal like:

0.010

remember, to the right of the decimal spot the order goes:

tenths > hundredths > thousandths

now, to express this witha  negative exponent, you count back (to the right) the number of spaces until you can see/make a number that is between 1 and 10

so, in this case the number you would make ends up to be 1.00 and you do this by moving to the right 2 spaces...therefore:

1.00 x 10 ^ -2

you take that number you made (1.00 by moving over 2 spaces) and multiply it by 10 to a certain power. the power is determined by the number of spaces you moved (so, 2 in this example) the negative indicated that this is a very small number, because you moved to the right. if you had moved to the left it the exponent would have been positive!

this notation is known as "scientific notation" and youll use it tons in math and science courses in the years to come!

another example:

write the number: 172.00 in scientific notation.

1. "find" a number between 1-10

2. do this by moving to the RIGHT2 spaces.

= 1.72

3. write in scientific notation:

1.72 x 10 ^ 2

and heres one more example:

Jimmy lost a 200 meter races by 4 tenths (4/10 or 2/5 if you prefer)of a second. Write in scientific notation

4 tenths of a second = 0.40

4.00 x 10 ^ -1

remember to put in units! itll take some practice, but youll get the hang of it!

Answer 3

10^-2 s

10 to the negetive second power. They just want it in like scientific notation thats all. Hope i helped.