11 Plus Exams Forum

How to divide decimal number by big whole number
For example

Mince cost £1.80 per 1/2kg
Find the cost of mince weighing 600g?

I am using 1.80/500x600 method on calculator but how to do on paper

Thanks

haniya11plus wrote:How to divide decimal number by big whole number
For example

Mince cost £1.80 per 1/2kg
Find the cost of mince weighing 600g?

I am using 1.80/500x600 method on calculator but how to do on paper

Thanks

How about
1) double it for a whole Kg
2) divide by 10 for cost for 100g
3) times by 6.

haniya11plus wrote:How to divide decimal number by big whole number
For example

Mince cost £1.80 per 1/2kg
Find the cost of mince weighing 600g?

I am using 1.80/500x600 method on calculator but how to do on paper

Thanks

1/2Kg = 500g = £1.80

500g = 5 x 100g

You want the cost of 600g

600g = 6 x 100g

Divide the £1.80 by the number of units of 100g it represents, then multiply this by the number of units of 100g you want to price up ...?

No need for all those 00s.

Sorry £1.80 / ?
Then multiply?

£1.80 divided by 5 (as in the 500g that cost £1.80) would give you the cost for 100g

Times that 100g cost by 6 to get the cost of 600g.

kenyancowgirl wrote:£1.80 divided by 5 (as in the 500g that cost £1.80) would give you the cost for 100g

Times that 100g cost by 6 to get the cost of 600g.

Thanks, KCG

I was trying to follow the 'give hints, rather than do the whole thing' rule, but obviously it doesn't always work .

Thanks ladies
X
Was having nightmares with these mental arithmetic questions with year 5 child

Why is a 5 year old doing this question? It's inappropriate.

In any question it's a good idea to estimate - what sort of answer are we expecting? 600g is more tha half a kg so the answer should be bigger

Its in Mental Arithmetic book 4
Prep for 11+ exams

Sorry - may I suggest you stop using this book? It really is not appropriate and 5 years old is too young anyway.