Go back to basic principles. Here's the number 1234 in base 10: (and I've just realised I made a mistake in the last post)
[table][tr][td]Weight[/td][td]10[sup]3[/sup][/td][td]10[sup]2[/sup][/td][td]10[sup]1[/sup][/td][td]10[sup]0[/sup][/td][/tr][tr][td][/td][td]1[/td][td]2[/td][td]3[/td][td]4[/td][/tr][/table]
1234[sub]10[/sub] = 1 * 10[sup]3[/sup] + 2 * 10[sup]2[/sup] + 3 * 10 + 4
(recall that any number raised to the power 0 is 1)
And here's 1234 in base pi:
[table][tr][td]Weight[/td][td]pi[sup]3[/sup][/td][td]pi[sup]2[/sup][/td][td]pi[sup]1[/sup][/td][td]pi[sup]0[/sup][/td][/tr][tr][td][/td][td]1[/td][td]2[/td][td]3[/td][td]4[/td][/tr][/table]
1234[sub]pi[/sub] = 1 * pi[sup]3[/sup] + 2 * pi[sup]2[/sup] + 3 * pi + 4
And here's 1234 in base 3+2i:
[table][tr][td]Weight[/td][td](3+2i)[sup]3[/sup][/td][td](3+2i)[sup]2[/sup][/td][td](3+2i)[sup]1[/sup][/td][td](3+2i)[sup]0[/sup][/td][/tr][tr][td][/td][td]1[/td][td]2[/td][td]3[/td][td]4[/td][/tr][/table]
1234[sub]3+2i[/sub] = 1 * (3+2i)[sup]3[/sup] + 2 * (3+2i)[sup]2[/sup] + 3 * (3+2i) + 4
It is left as an exercise to the reader to evaluate all these numbers in decimal.