1681
78 + 79 + 80 + 80 + 81 + 81 = 479
Yes, 800 plus 800 equals 1600. When you add these two numbers together, the sum is indeed 1600.
81
9
The sum of 162 and 81 is 243.
78 + 79 + 80 + 80 + 81 + 81 = 479
81*82/2= 3321
105 + 66 + 287 + 81 = 539
-81
81
-81 + 11 = -70
18 + 81 = 99
-81 + 623 = 542
9
81 + 36 = 117
-81 + 43 = -38
(-11) + (-89) + 5 + (-67) + (-81) + (-27) = -270