Question

I write each number in expanded form:
6.458 = _ + _+ _ + _

Answer 1

6.458 = 6 + 0.4 + 0.05 + 0.008

Explanation:

6.458

---------------------

6.000

0.400

0.050

0.008

6.458 = 6.000 + 0.400 + 0.050 + 0.008

trailing zeros can be omitted

Answer 2

6.458 = 6 + 0.4 + 0.05 + 0.008

Each blank slot is filled with a digit from the original number. The zeros are placeholders to make sure we have the right alignment.