Pokémon math!

okay...
so you chose a Pokémon by it's national dex number (use the name, as an online Pokédex is easy to come by for the numbers)
then you chose one of the four basic arithmetic operations (+for addition, - for subtraction, * for multiplication, and / for division)
and then you chose another Pokémon to finish it off.
the next person answers, then posts their own problem
also, division must be rounded up or down to the nearest whole number in case of decimals.

examples:

I'll start!
volbeat / ratatta = ?

Error. I mean, um...Pidgey.

Bulbasaur * Charmander / Squirtle

well, that rounds up to wartortle... I think
victini-celebi+mew

It's 0.5714285714285714(etc.), so it's either Bulbasaur or Missingno., actually.

The answer to yours is Prinplup, so:

Grotle (the evolution of Turtwig) + Monferno / Prinplup = ?

388 + 391 = 779 / 394 = 1.97715736041

Rounding that up, that leads to Ivysaur.

Mew + Mewtwo + Pikachu = ?

well that's 327 so... spinda.
dedenne - klefki + dexoys = ?

You're off by one.

702 - 707 = -5 + 386 = 381

Latios

Mew x Venusaur - Raichu + Charmander = ?

dammit!!!!
anyway... bronzor
crogunk + lucario = ?

Off by 5 this time.

And there's no Pokémon with a number of 901...

Edit: Forgot something:

Plusle + Minun = ?

oops, I meant crogunk-lucario, but that's negative so 
corgunk - lucario + riolu = ?
also I did it on a calculator, so how did I not get it?

Mew x Venusaur - Raichu + Charmander = Glameow

151 x 3 = 453 - 26 = 427 + 4 = 431

And for the other one:

Mew + Mewtwo + Pikachu = Grumpig

151 + 150 = 301 + 25 = 326

You derped up on the calculations?

Plusle + Minun= Golurk (go lurk elsewhere, you creep!)
Corgunk (I take it you mean Croagunk?) - Lucario (croagunk - lucario isn't negative, but what evs.) +Riolu= Drapion

Salamence - Groudon + Charizard + Jirachi = ?

yeah...

I'm rebooting this thread...
two new rules
1. NEW AND SHINY (pun not intended) negative Pokédex!
(meaning we can now go up to 719 in either positive or negative in our equations
2. there is a missingno. (zero can be included as a result of the 719 negative pokemon)
also, bunnies answer is latios
negative ditto+ darkrai-negative shaymin+ mew.

Why would you need a) negative numbers b) zero/Missingno. and c) this thread to be rebooted.

Anyway, there is no Pokémon with a 'dex number equal to...1002. Yes, I did it correctly - subtracting a negative number is akin to adding a positive number.