Steve, the Torah is not the Chumash and visversa.
The Chumash is the Torah but set up differently so the words aren't interchangable. The Chumash has the five books but it is set up on the manner of the weekly reading schedule and the hatarah scriptures inserted there as well. The CJB is also set up this way on the five book of Torah contained in it.
It can sometimes be referred just as the five, but more commonly it refers to a specific set up with the parshot.
Something else good to add is why the Torah books are called what they are called in Hebrew. The names are taken from the first word in the books. I will give the meanings below
B'reshit - Genesis - ( In the) Beginning' just as Gen 1:1 says, In the beginning G-d created the heavens and the earth.
שמות
Sh'mot - Exodus - ( comes from the word Shme, meaning 'name') sh;mot is the plural and means ' names'. Ex 1:1 starts, 'These are the names of the sons of Israel..........'
ויקרא
Vayiqra - Leviticus- 'He called' is what Vayikra means. Lev 1:1 says ' Adonai called to Moshe..................'
במדבר
B'midbar - Numbers - B' midbar means, 'in the desert'. Num 1:1 starts: ' Adonai spoke to Moshe in the Sinai Dessert ( or wilderness)............'
דברים
D'varim - Deuteronomy - D'var means word, and D'varim means 'words' Deut. 1:1 says: 'These are the words Moshe spoke to all Israel......................'
Notice the last three of the books are all addressing Moshe in one way or another.