200
George has 138 baseball cards, 151 football cards, and 129 basketball cards. He calculated that he has 418 sports cards in all. Which is the BEST number sentence to use to see if George's answer is reasonable?
A) 110 + 120 + 130 = 360
B) 130 + 130 + 130 = 390
C) 140 + 150 + 130 = 420
D) 110 + 120 + 130 = 360
What is "C". 139 rounds to 140, 151 rounds to 150, and 129 rounds to 130, so 140+150+130=420 is the BEST number sentence to show that George's answer of 418 is reasonable.