77. 0.205 < 0.21
It's less by 0.005
78. 0.1 = 0.1000
The extra zeroes do not change the solution.
79. -0.04 > -0.050
While this might look greater, remember to check the number line position
80. -1.03 < -0.03
Same as the last one.
81.

< 0.6

= 0.5 < 0.6
82. -

< -0.03
Same process as 80 mixed with 81.
I hope that these help.