You are Here: Home >< Maths

# Maths

1. Can someone help me work out this question?

M= 7.1 x 10 to the power of 6
N = 3.2 x 10 to the power of -3

Work out in each case giving your answer in standard from to 3sf

a) mn

b) m over n

Posted from TSR Mobile
2. multiply the numbers (7.1 times 3.2) and add the exponents (+6 - 3) to get M*N = (7.1*3.2) x 10^(6-3) = 22.72 x 10^3

Then to get it back in standard form, you need the first bit to look like "X.XX", so re-write 22.72x10^3 as 2.272x10^4. Note that you divide the first bit by ten and then raise the exponent by one.

The same method can be applied for the second method. Give it a go. (remember 1/(x^a) == x^(-a), i.e. the exponent sign goes negative when you move from denominator to numerator)
3. mn = (7.1 x10 ^6 ) x (3.2 x10^-3) first multiply 7.1 by 3.2 then consider what happens to the powers of 10 for example 500 x 20 = 10,000 and notice whats happened to them in this sum and apply it to your own and similarly for part b) m/n look at for example 5000/50 = 100
4. Thank you!😄

Posted from TSR Mobile

## Register

Thanks for posting! You just need to create an account in order to submit the post
1. this can't be left blank
2. this can't be left blank
3. this can't be left blank

6 characters or longer with both numbers and letters is safer

4. this can't be left empty
1. Oops, you need to agree to our Ts&Cs to register

Updated: October 14, 2016
TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Today on TSR

What do you wish you'd be taught?

Poll
Useful resources

### Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

### How to use LaTex

Writing equations the easy way

### Study habits of A* students

Top tips from students who have already aced their exams