De or het schematje?

The correct Dutch article is:

het schematje

Rule Diminutives (-je, -tje, -pje): always het. See the rule

This word is not in the word lists we use to double-check answers.

How to use schematje

the schematjehet schematje
this schematjedit schematje
that schematjedat schematje
our schematjeons schematje
your schematjejouw schematje
every schematjeelk schematje
which schematje?welk schematje?
a big schematje / the big schematjeeen groot schematje, het grote schematje