Question

Estimate each quantity in terms of powers of ten.

2^70

4^90

Answer 1

we know that 2^10 = 1024 which is approximately equal to 10^3
so 2^70 = (2^10)7 = (10^3)^7 = 10^21

Answer 2

these are of course approximate values

Answer 3

The question is to estimate, after all.

Answer 4

4^90 = (4^5)^18 = (2^10)^18

2^10, as dhatraditya said, is 1024, which is roughly 10^3

= (10^3)^18 = 10^54