dividing with decimals

[BLANCA]

Can anyone please explain this to me

instruction: divide the following and round answer to 2 decimal places

question:- 65.35 / 1.3 answer = 0.129


any help greatly appreciated

[Guest55]

Something wrong here as the answer you have given has 3dp!

[BLANCA]

sorry, looking at wrong answer the correct answer is 50.27 but the example in the book is not great and i'm still having trouble working out how to do these sums, so please help if you can.

many, many thanks

[Guest55]

Usually I would encourage pupils to make sure the number they are dividing by is a whole number so:

65.35 / 1.3 = 653.5 / 13


which will give the same answer - first estimate 650 /10 is roughly 65

What method are you trying to use 'chunking' or 'short division' (Bus stop)

653.5 13 x 50 = 650

653.5 - 650 = 3.5 this is chunking as I'm taking 'chunks off'

3.5 /13 13 x 0.2 = 2.6

3.5 - 2.6 = 0.9

0.9/ 13 13 x 0.06 = 0.78 13 x 0.07 = 0.91 which is nearer

so answer is 50.27 (to 2 dp)

If it's short division you need to look at:

http://www.mad4maths.com/math_help_division/

[BLANCA]

thank you so much, we were only making the 1.3 into whole number and not moving decimal for 65.35 also thanks for the link.

[Guest55]

It's better to talk about multiplying both numbers by ten -

[BLANCA]

how do you mean?

[Guest55]

It is not recommended to talk about moving decimal points - if you multiply both numbers by 10 you get whole numbers.

[BLANCA]

I see,

thank you it's much appreciated

[tipsy]

65.35/1.3 - multiply until divisor is a whole number i.e. 13

653.5/13 and then do a short division.

If the sum was 23.6/0.14 you would need to multiply the whole thng by 100 so that you were dividing by 14:

2360/14