If a = 2.8x10^5 and b=1.6 x 10^6, give the values of i) a +b and ii) a x b

Find from student what the first step is (get a or b in terms of the other).  

a = 2.8 x10^5 = 0.28x10^6

a + b = (0.28 + 1.6) x 10^6

= 1.88 x10^6

ii)

Know that a^x x b^y = ab^x+y

.: 2.8 x 1.6 = 4.48

10^5 x 10^6 = 10^11

a x b = 4.48x10^11