Each material class of similar and dissimilar item should be presented separately in the financial statements. There’s no other option when it comes to material items. 

Where does the line of “material” run though? IAS 1 in paragraph 1 states that Omissions or misstatements of items are material if they could, individually or collectively, influence the economic decisions of users taken on the basis of the financial statements. So it really is judgmental and highly dependent on how management measures it.

Steps to measure are first off defining the users and then looking at the size and nature of the omission or misstatement. Wherever the management sees a class of an item material enough according to the definition given, it’s to be presented separately and not aggregated into other items.

On a side note, an immaterial line item is aggregated with other items either on the face of the primary statements or in the notes. It may very well be that what’s considered as immaterial on the face of the statements to be presented on it’s own, may be material enough to be disclosed separately in the notes. The reason for this is simple – notes are break down of the items presented on the main statements and as such, the “materiality” is lower for the information given there.