Express in scientific notation - immediately

4.) Add your like numbers, 3.6, 4.0 and 10^-2, 10^-1. 3.6+4.0=7.6. 10^-2+10^-1= 10^-3

so 7.6+10^3

6.) 13.4+10^10

well there are two answers for that.

1: you need 120 ones then that will equal up to 120.

2: you could also do one 100 and 2 tens.

those are the answers that i have thought of.