29 x 51

First of all, notice that 3 x 51 = 153, so 30 x 51 = 1530. Now, notice that 29 = 30 - 1, so 51(29) = 51(30 - 1) = 1530 - 51 = 1500 - 21 = 1479. ---Alternately, 30*50 = 1500. That's thirty 50's, so if we subtract 50, we get 29*50 = 1450. That's fifty 29, so add 29 to get 29*51 = 1479.