Is there a formula for 3 (or more)-digit numbers similar to this?
ab*cd=xyz
z=b*d
y=a*d+b*c
x=a*c

Question

Is there a formula for 3 (or more)-digit numbers similar to this?
ab*cd=xyz
z=b*d
y=a*d+b*c
x=a*c

anonymous · Answer

@Michalas @amistre64

amistre64 · Answer

not sure what the question is asking

ganeshie8 · Answer

what would you do if b*d results in two digits ?

ganeshie8 · Answer

i think the OP is looking for a shortcut for multiplying two 3 digit numbers...

ganeshie8 · Answer

for example : 

28 * 37

b*d = 8*7 = 56

amistre64 · Answer

ab
cd
---
ac + bc
       ad + bd
-----------
x      y        z

so its just multiplication ....

amistre64 · Answer

you could develop one ... just multiply 3 digit numbers

amistre64 · Answer

abc
xyz
-----
ax + bx + cx
         ay + by + cy
                 az + bz + cz
---------------------
 m        n     o     p       q

ganeshie8 · Answer

looks like we get a formula similar to determinant of 3x3 matrix to me :)

amistre64 · Answer

what?  thats just crazy talk .... absolutely mad i tell ya

ganeshie8 · Answer

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