Lizzy: 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?.
Me: Hmmm, let me think. I think this is the detailed solution:
He grows six inches a year because 12 x .5 = 6. He will grow 24 inches between his 8th and 12th birthday because 4 x 6 = 24. He will be 74 inches tall because 50 + 24 = 74. Final answer: 74.