maths

[Tichy]

How do you work this out please?

A path has to be laid which is 9 and two third slabs long by 2 and half slabs wide how many slabs are need to lay the path assumming no waste ?

(Paving slabs can be cut to size)

[sophie_1003]

9x2=18

0.5x9=4.5 you would need 5 whole slabs but could cut one in to three pieces, so you effectivley get one half a slab and one third of a slab

plus the one extra to get the other third

so it would be 24 in total, I think!

[sophie_1003]

sorry just realised was TWO thirds, errrm

9x2=18

0.5x9=4.5 (would need 5)

2 extra to get the two thirds from

25 in total

[shehin]

I think you would need 25 slabs in total (if my quick sketch is accurate)

18 for the 9 x 2 main part, uncut slabs

5 need to be cut in half to create the 9 x 1/2 slabs, leaving one x 1/2 slab which you would need to cut again to make a slab 1/2 x 2/3.

Finally, you need 2 slabs cut to 2/3rds width. You would be left with 2 x 1/3rd pieces left over.

[Hammer]

I think this is a simple multiplication question, set out in a way to make you think a bit.

It's asking you the area of a rectangle with sides of 9.6666 and 2.5, or 'what is 9.666 x 2.5'?

Answer is 24 and a bit, so you need 25 slabs.

[Andy Boz]

9 and 2/3 is ten, multiplied by 2 1/2 is 25.

You would have problems asking at a builders merchants for two thirds of a slab.

It is a simple multiplication, but with the twist that you have to start with whole slabs.

Assuming no waste, how many tea breaks would be needed?

[Space]

I think that "assuming there is no waste" means that we don't have to worry about rearranging the cut slabs, so we only have to calculate the surface, just like Hammer did.

[TEAK36]

Hi Tichy, I recently laid a fairly complicated patio,and was finding it very difficult to work things out.I found a small downloadable program on www.Bradstone.com, and all you do is enter the size of the area you want to lay,then select from the various types and sizes of slabs, and the program tells gives you loads of patterns you can choose from, and tells you exactly how many slabs you need for each pattern.It was really accurate.You might have to navigate around the site to find the download,but it is well worth it.

[Banjoman]

Have a look at this site. then look for the "True Cut" tool. Its fab>
http://www.tclproducts.co.uk/c_000009.htm

[Tim B]

If you change it to minimal waste then:-

nine and two thirds = 29/3

two and a half = 5/2

multiply 29/3 * 5/2 = 145/6 = 24 and 1/6 slabs = 25 whole slabs but 5/6 of a slab is wasted.

[brachiopod]

Don't take the "no waste" bit of the question to mean "no remainder" or "no bits left over".

It's implying that you don't make a mistake and cut a slab to the wrong size, or if cutting it the old-fashioned way (with a hammer and bolster), you don't get a slab cracking in totally the wrong place, so the whole slab is wasted as it can't be used.

If doing this in real life, yould probably buy a few slabs over what you require to allow for mistakes when cutting.