Hugh Henry of Melbourne has made available a nice setting of the grace before meals in Latin. It's not only a great way to learn to memorize Latin (I find singing Latin easier than saying it); it also provides a nice entry into chant for the whole family.
To sing it, think of the lowest note first, and move up a 5th, as in Twinkle, Twinkle. You start on the note of the second word in that song. The lowest note in this chant occurs toward the end on Tu-ri. That's where your are headed. The remaining notes can intuited with Do, Re, Mi. The first note is Do and the next note, moving down the scale, is La. Hold the notes with the note an extra pulse. That's all there is to it.
Here is a PDF edition to print. Here is an MP3 audio sample.