BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

very silly question

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
User avatar
Legendary Member
Posts: 659
Joined: Mon Dec 14, 2009 8:12 am
Thanked: 32 times
Followed by:3 members

very silly question

by Gurpinder » Sat Aug 14, 2010 7:15 am
453.122 x 10 = 4531.22

453.122 x 10^3 = 453122

453.122 x 10^-2 = 4.53122 ????????????????

so when we have a negative exponent like this one, do we simply move the decimal to the left based on what the exponent is.

so if the exponent is -2, do we go 2 places to the left or 3???

thanks to all
"Do not confuse motion and progress. A rocking horse keeps moving but does not make any progress."
- Alfred A. Montapert, Philosopher.
Top
Source: — Problem Solving |
Master | Next Rank: 500 Posts
Posts: 345
Joined: Wed Mar 18, 2009 6:53 pm
Location: Sao Paulo-Brazil
Thanked: 12 times
GMAT Score:660

by shibal » Sat Aug 14, 2010 7:58 am
Gurpinder wrote:453.122 x 10 = 4531.22

453.122 x 10^3 = 453122

453.122 x 10^-2 = 4.53122 ????????????????

so when we have a negative exponent like this one, do we simply move the decimal to the left based on what the exponent is.

so if the exponent is -2, do we go 2 places to the left or 3???

thanks to all
when exponent is negative you go left. you said -2, thus you go 2 spaces to the left

i.e. 95400 * 10^-3 = 95.4
i.e2. 95400 * 10^-4 = 9.54
i.e.3 95400 * 10^-5 = 0.954

hope it helps
best
Top
User avatar
Legendary Member
Posts: 659
Joined: Mon Dec 14, 2009 8:12 am
Thanked: 32 times
Followed by:3 members

by Gurpinder » Sat Aug 14, 2010 8:10 am
shibal wrote:
Gurpinder wrote:453.122 x 10 = 4531.22

453.122 x 10^3 = 453122

453.122 x 10^-2 = 4.53122 ????????????????

so when we have a negative exponent like this one, do we simply move the decimal to the left based on what the exponent is.

so if the exponent is -2, do we go 2 places to the left or 3???

thanks to all
when exponent is negative you go left. you said -2, thus you go 2 spaces to the left

i.e. 95400 * 10^-3 = 95.4
i.e2. 95400 * 10^-4 = 9.54
i.e.3 95400 * 10^-5 = 0.954

hope it helps
best
ok.....so when i do this 4x10^-2 --- why do i get .4 when the book says that its .04 ?????

10^-2 = .1

and .1x4 = .4

what am i doing wrong!!!!
"Do not confuse motion and progress. A rocking horse keeps moving but does not make any progress."
- Alfred A. Montapert, Philosopher.
Top
User avatar
Legendary Member
Posts: 1893
Joined: Sun May 30, 2010 11:48 pm
Thanked: 215 times
Followed by:7 members

by kvcpk » Sat Aug 14, 2010 8:42 am
Gurpinder wrote: ok.....so when i do this 4x10^-2 --- why do i get .4 when the book says that its .04 ?????

10^-2 = .1

and .1x4 = .4

what am i doing wrong!!!!
10^-2 =1*10^-2
So now, put the decimal dot(.) 2 spaces before 1.(including 1)
Hence 0.01

4* 10^-2
Hence = 0.04

Hope this helps!!
"Once you start working on something,
don't be afraid of failure and don't abandon it.
People who work sincerely are the happiest."
Chanakya quotes (Indian politician, strategist and writer, 350 BC-275BC)
Top
User avatar
GMAT Instructor
Posts: 3225
Joined: Tue Jan 08, 2008 2:40 pm
Location: Toronto
Thanked: 1710 times
Followed by:614 members
GMAT Score:800

by Stuart@KaplanGMAT » Sat Aug 14, 2010 9:35 am
Gurpinder wrote:453.122 x 10 = 4531.22

453.122 x 10^3 = 453122

453.122 x 10^-2 = 4.53122 ????????????????

so when we have a negative exponent like this one, do we simply move the decimal to the left based on what the exponent is.

so if the exponent is -2, do we go 2 places to the left or 3???

thanks to all
Hi!

A negative exponent is the same as the reciprocal of the positive exponent.

For example, 2^(-4) = 1/(2^4)

So, when you multiply by 10 to a negative exponent, you're really dividing by 10 to the positive exponent.

Using your example:

453.122 x 10^-2 = 453.122 / 10^2 = 453.122 / 100 = 4.53122

As you noted, this simply means that you move the decimal to the left for negative powers of 10 and to the right for positive powers of 10.

Similarly:

4 x 10^-2

= 4 / 10^2

= 4 / 100

= .04
Image

Stuart Kovinsky | Kaplan GMAT Faculty | Toronto

Kaplan Exclusive: The Official Test Day Experience | Ready to Take a Free Practice Test? | Kaplan/Beat the GMAT Member Discount
BTG100 for $100 off a full course
Top
Post new topic Post Reply
• Page 1 of 1