Alexander was 50 inches on his 8th birthday. If he grows 1/2 a foot a year, how many inches tall will he be on his 12th birthday?
He grows six inches a year because 12 x .5 = <<12*.5=6>>6
He will grow 24 inches between his 8th and 12th birthday because 4 x 6 = <<4*6=24>>24
He will be 74 inches tall because 50 + 24 = <<50+24=74>>74
#### 74