SOLUTION: How do i solve 49 times 19... Mentally?

Question 745006: How do i solve 49 times 19... Mentally?
Found 2 solutions by stanbon, Alan3354:
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
How do i solve 49 times 19... Mentally?
-------
49*19 = (50-1)(20-1) = 1000-50-20+1 = 931
==================
Cheers,
Stan H.
Answer by Alan3354(69443) (Show Source): You can put this solution on YOUR website!
How do i solve 49 times 19... Mentally?
----------------
There are many ways for this one.
---
= 19*7 then *7
= 19*50 then -19 the best for this one, imo
---------------
Another method, not so attractive for this one is
Get the average = (49 + 19)/2 = 34
Diff between ave and numbers = 15
49*19 = avg^2 - diff^2 = 1156 - 225
This works well for a lot of them, not so good for this one.
eg, 37*39 = 1443 easily (if you know what 38^2 is)

RELATED QUESTIONS
How do I explain how I can use the Commutative and associative properties to add 19+28+81 (answered by JulietG)
How do you solve; i^49... (answered by jim_thompson5910)
How do i evaluate 8+5 to the second power mentally? (answered by Earlsdon)
22 is 74% of... How do I calculate mentally? Thank you! (answered by solver91311)
how do I solve... (answered by unlockmath)
How do I solve 7 +... (answered by rfer)
How do you solve and get the answer to 19 over 49 in a radical sign? (answered by jsmallt9)
How do I solve... -2x+3=+49... (answered by luvalady9)
how do i solve... (answered by Fombitz)