(i) 1.008 < 1.800
The whole parts are equal, and comparing the tenth parts, we have 0 < 8.
Therefore, 1+ 0/10 +8/1000 < 1+8/10.
(ii) 3.3 = 3.300
The whole parts and the tenth parts are both equal.
(iii) 5.64 > 5.603
The whole parts and the tenth parts are both equal. Comparing the hundredth parts, we have 4 > 0.
Therefore, 5+ 6/10 + 4/100 > 5 + 6/10 + 0/100 + 3/1000.
(iv) 1.5 = 1.50
The whole parts and the tenth parts are both equal.
(v) 1.431 < 1.439
The whole parts, the tenth parts and the hundredth parts are all equal. Comparing the thousandth parts, we have 1 < 9.
Therefore, 1+ 4/10 + 3/100 + 1/1000 < 1+4/10 + 3/100 + 9/1000.
(vi) 0.5 > 0.05
The whole parts are both 0. Comparing the tenth parts, we have 5 > 0.
Therefore, 5/10 > 0/10 +5/100.