30 times.
Mainly the commutative property. But the fact that 30*8*7 is unambiguous and you do not need to write (30*8)*7 or 30*(8*7) is due to the associative property.
Ten times.
4.285714285714286
7 times with 23 remaining 233 - 23 = 210 = 7 x 30
Its a miracle !! * * * * * That is one way of looking at it! Here's another: 300 * 7 = (30 * 10) * 7 which, by the associative property of multiplication, = 30 * (10 * 7) = 30 * 70 and there's the miracle!
Yes: 300 x 7 = 2,100 30 x 70 = 2,100
7/10 * 30 = 0.7 * 30 = 21
210 = 7 x 30 so 30 times with 6 remaining
44
The Answer is 42 (7x6=42) seven times six is 42.
30