Crossword Genius

Adding up to a support (9)

Ross

I believe the answer is:

amounting

I'm a little stuck... Click here to teach me more about this clue!

'adding up' is the definition.
(I've seen this in another clue)

'a support' is the wordplay.
I cannot quite understand how this works, but
'a' is found in the answer.
'support' could be 'mount' (I've seen this before) and 'mount' is found in the answer.
This explanation may well be incorrect...

'to' acts as a link.

Can you help me to learn more?

(Another definition for amounting that I've seen is " Being equivalent".)

I've seen this clue in The Daily Express.
Want a hint initially instead of a full solution? Install my app