mathematics for elementary school teachers

K

kelly28

New member
Joined
Oct 15, 2010
Messages
3
The problem is a multiplication problem using a left to right multiplication method. The example given is...
731
x238
_____
1462 (2x731)
2139 (3x731)
5848 (8x731)
___________
173978

The problem I need to figure out is 768x891
I understand that I need to do 8x768, 9x768, and 1x768 leaving me with a problem that looks like this:

768
x891
_________
6144 (8x768)
6912 (9x768)
768 (1x768)
_____________

However, I dont understand how the answer is obtained from these numbers. Help!
 
kelly28 said:
The problem is a multiplication problem using a left to right multiplication method. The example given is...
731
x238
_____
1462 (2x731)
2139 (3x731) <=== Should be 2193
5848 (8x731)
___________
173978

The problem I need to figure out is 768x891
I understand that I need to do 8x768, 9x768, and 1x768 leaving me with a problem that looks like this:

768
x891
_________
6144 (8x768)
6912 (9x768)
768 (1x768)
_____________

However, I dont understand how the answer is obtained from these numbers. Help!
Click to expand...




Hi kelly28,

There's a typo in your example. 3 X 731 = 2193.

Anyway, You are to add the columns noting the place values.

The first number is "hundreds", the second is "tens" and the last one is "ones".

So, you're essentially adding:

614400
+69120
+++768
----------
684288
 
kelly28 said:
Denis said:
Are you an "elementary school teacher" ?
Click to expand...
Not yet... hence, why I am in college...
Click to expand...
Good luck...
This is the way I was taught (many years ago!):
Code: 
        7 6 8
        8 9 1
        =====
        7 6 8
    6 9 1 2
  6 1 4 4
  ===========
  6 8 4 2 8 8
 
You must log in or register to reply here.
Top