Clarification about Tools in Stone Age

I just got Stone Age as a gift and I've played it one time so far. But I have a question about how the tools work.

They way we played from how I understood the rules:

A player places two people and decides to use 1 value-1 tool to gather wood in the forest. Thus the player rolls 3 dice (2 for people, one for tool). He rolls 3+4+5 = 12. Divides that by 3 and takes 4 wood.

This quickly resulted in not having enough dice to handle a single job. Considering you could place 5 people and use 8-value tools which means you'd need 13 dice.

I read online that other people play this way:

A player places two people on wood. Rolls two dice, gets 2+3=5. Then decides to use 1 value-1 tool to up his sum to 6 which lets him get 2 wood instead of 1.

Which way is correct?

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I am unaware of the official rules, but if you need to roll more dice at once than you have available, why not roll them multiple times and add up the results? – Hackworth Feb 3 '12 at 10:49
That is what we ended up doing, but one player thought it shouldn't be allowed. – jb. Feb 3 '12 at 17:16