1 x 1 + 7 x (1/10) + 4 x (1/100) + 7 x (1/1000)
It's in expanded form. If you break it apart...
1x1 = 1 (ones place)
7 x 1/10 = .7 (tenths place)
4 x 1/100 = .04 (hundredths place)
7 x 1/1000 = .007 (thousandths place)
Now if we add the results
1 + .7 + .04 + .007 = 1.747