Respuesta :

Word form: three and four tenths. Expanded form: 3 + 0.4 = 3.4
Word Form: Three and four tenths. 

(when saying the decimal point, you use and.)

Expanded Form: 3 x 1 + 4 x 0.1 = 3.4

(There are many different ways to write expanded form. The one I wrote above it one of many.)

Hope this helps! :)