Math Is Fun Forum

Print out plenty of worksheets, and practice. The worksheets are here. You can also print the answer sheet for each worksheet.

Just resist the temptation to use your pen to help you solve them. Look at the question, do the maths in your head, write the answer. Then when you finish the sheet, compare with the answers and try to figure where you went wrong.

You WILL get better with practice.

By the way, every person develops their own way to do mental maths, because there are many different ways around each problem.

For example, 18 times 2 could be worked out as:

a) 10 times 2 plus 8 times 2 = 20+16 = 36
b) 20 times 2 minus 2 times 2 = 40-4 = 36
c) 9 times 2 times 2, or 9 times 4, and 9x4=36
d) some other way?

Sabre Rattling !!

I am getting the feeling this one can't be solved.

I will have a go at Q3 now, but then I have to go do something else for a while ...

"A pool can be filled with water by a large pipe within 6 hours. A smaller pipe will take 9 hours to fill the pool. How long will it take to fill the pool if the two pipes operate together?"

Hmmm .. let us imagine that the big pipe can pump 1000 litres an hour. I could say "x" an hour, but let's just try with some real numbers for a change.

So the pool would get 6,000 litres in 6 hours.

Now, the smaller pipe takes 9 hours, so it must be pumping 6,000/9 = 666 litres an hour.

TOGETHER (assuming they still work just as well) they would pump 1,000+666 = 1,666 litres an hour.

So it would take 6,000/1,666 = 3.6 hours

If this is homework, you should use proper algebra, something like:

Let x be the rate of flow of the large pipe.

The rate of flow of the small pipe is (6/9)x

The flow rate together is (1+6/9)x

Now, we know that a flow rate of "x" takes 6 hours, so a flow rate of (1+6/9)x should take 6 / (1+6/9) hours:

Time = 6 / (1+6/9) hours

Multiply top and bottom by 9 to simplify:

Time =  9*6 / 9*(1+6/9) = 9*6 / (9+6) = 54/15 = 3.6

We have some pages you might like to look at on long division at long division

To solve your example:

38  ) 4567

Work on the first two digits of 4567:

38  ) 4567
        45

Try the biggest multiple of 38 that fits into 45, which is 1. Write down the 1 above, and subtract the 38 (45-38=7):

          1
38  ) 4567
        45
       -38
          7

Now, bring down the next digit, 6:

          1
38  ) 4567
        45
       -38
          76

Now find the biggest multiple of 38 that fits into 76, which is 2 (and by luck is exaclty 76):

          12
38  ) 4567
        45
       -38
          76
          76
            0

Now, bring down the last digit, 7:

          12
38  ) 4567
        45
       -38
          76
          76
            07

This is the last digit, and 38 cannot fit into this, so it is the "remainder":

          120  Remainder 7
38  ) 4567
        45
       -38
          76
          76
            07

So, 4567/38 = 120 with a remaidner of 7/38

My calculator gives 4567/38 as 120.18, so it looks right.

Hows that?

Very Impressive!

Noni, you are welcome here any time ... why not Register and upload an image to represent yourself (called an Avatar).

I will look into it. I mean how hard can it be, right?

Well, for a ferret, you sure had some confused humans over in the Guest Forum.

Oh, and Welcome!

Post them into the "Members Only" section, and I can then take a copy of the solution and then delete it off the forum.

Hey, Rora, you should use an Avatar - find a small image that you want to appear next to your name (up to 60x60 pixel) and upload it from your Profile under Personality.

Oh NOOO!