What, exactly, does the game mean when it says that spells will do x+x damage? For example:

Hell Spikes
Call on the netherworld to shoot spikes under the feet of your opponents
Level 1-
A maximum of 1 spike can be summoned
The spike does three times 4+10 damage
Required Level: 1
Magic Cost: 2

Does this mean the spike will do 3 * ( 1d4 + 1d10 ) damage?

Thanks,
-Mike