03-types should cover declarations

[stellentus]

var id type = val
id := val

Examples:
var num int = 16
var num int Now num has the zero value
num := 16
num := int64(16) Now num is an int64 instead of an int. Note the syntax is similar to calling a function called int64 with the argument 16.

[stellentus]

Also
var num = 16 Note the type is inferred

[stellentus]

Take a look at the "Explicit type conversions" slide in 09-struct.slide. I think some of that should show up in this talk, since the students have needed to do some type conversions already.