multiplcation & divison???????????

Question

can anyone give me help or ways to multilpy or divide large numbers e.g

320 x 800

320 / 800 (divided(

1589 x 1787

1589 / 1787 etc

Im useless at it ang have my gcse math tomorrow please help

Answer 1

The easiest way is keep things simple.

320 x 800
Think of it as 8 times 32. Eight twos are 16 and eight threes are 24, so eight thirties must be 240. That must be 256, then. Now think about how many noughts. The answer must be under 320,000 because 800 is less than 1,000. So it must be 256,000!

320 / 800
Obviously 800 can't go into 320, so the answer will be less than 1. Try 8 into 32 instead. Easy! It's 4. So the answer must be 0.4!

Answer 2

320 x 800

Multiply 32 by 8 and add 3 zeroes to the right side.

32 X 8 = 256 and we add three 0s getting 256000

320 / 800 = 32 /80 = 4 / 10 = 2 / 5 = 0.4

1589 x 1787 = 1600 X 1787 - 1787

1600 x 1787 = 2859200 - 1787 = 2857413

The last one has no short cut and needs brute method.

Answer 3

1589 x 1787
A crash course im multiplicatin. Write the 2 numbers directly under each other

1589
1787
____

Multiply by the 7 first, w.rite the ans underneath

' 1589
' 1787
____
11123

I trust you can do the carrying and all that.
Next line, put a 0 at the right & multiply by the 8. (you;ve put the 0 down, so you're actually mutliplyig by the 80)

' ' 1589
' ' 1787
_____
' 11123
111320

Next line, add two 0s' to the right and multiply by the 7 (the 700)

' ' ' 1589
' ' ' 1787
_____
' ' 11123
' 111320
1112300

Now, three 0's and x by 1 (by 1000)

' ' ' 1589
' ' ' 1787
_____
' ' 11123
' 111320
1112300
1589000

Now, draw a line under and add the 4 lines together.

' ' ' 1589
' ' ' 1787
_____
' ' 11123
' 111320
1112300
1589000
_______
2823723 Hey presto, your answer.

Answer 4

multiplying:

put them in a grid and add up the results: eg 452 x 29

//////////////20////////////9
400 8000 + 3600 = 11600
50 1000 + 450 = 1450
2 40 + 18 = 58

answer = 11600+1450+58 = 13108

Division: Example 738/18

18 l 738.0000

see how many 18s go into 73 for example

Answer 5

320*800
=32*8*10*100
=512000
320/800
=(32*10)/(80*10)
=32/80
=(16*2)/(16*5)
=2/5
Others are too difficult to explain - You need a paper.

Answer 6

when there are zeros in the question just count the zeros and multiply the whole numbers: 32000 x 80=2560000 and do the same with division

Answer 7

I thought that these days nobody was taught multiplication and division as calculators are used all the time. You have just proved it.

Answer 8

Sorry sweetheart but its abit late a night to start using my brain now.