Problem:
100×19.98×1.998×1000=
Answer Choices:
A. (1.998)2
B. (19.98)2
C. (199.8)2
D. (1998)2
E. (19980)2
Solution:
Use the associative property to group as follows: (100×19.98)×(1.998×1000)=1998×1998=(1998)2.
Answer: D.
The problems on this page are the property of the MAA's American Mathematics Competitions