The expression from part A is 1 × 108 • 2 × 10-8. Apply the Commutative and Associative Properties of multiplication to get 1 × 108 • 2 × 10-8  = 1 • 108 • 2 • 10-8       (using the Associative Property) = 1 • 2 • 108 • 10-8        (using the Commutative Property) = (1 • 2) • (108 • 10-8)       (using the Associative Property) Part C Now that the first factors are grouped and the powers of 10s are grouped, multiply the first factors in the expression from part B. Then multiply the powers of 10 by using the properties of exponents.