Hello There!
"Percent" means "per 100" or "over 100". So, to convert 0.007 to percent we rewrite 0.007 in terms of "per 100" or over 100.
Multiply 0.007 by 100/100. Since 100/100 = 1, we are only multiplying by 1 and not changing the value of our number.
X
=

Therefore, we have shown that
0.007 = 0.7%