ASCII Codes in WORD for Mac

When writing WORD documents on a PC, I am a frequent user of mathematical symbols: § (alt 21), ½ (alt 171), α (alt 224), ß (alt 225), π (alt 227), Σ (alt 228), σ (alt 229), µ (alt 230), τ (alt 231), Θ (alt 233), Ω (alt 234), δ (alt 235), φ (alt 237), ε (alt 238), ± (alt 241), ≥ (alt 242), ≤ (alt 243), ÷ (alt 246), ≈ (alt 247), ° (alt 248), ∙ (alt 249). These symbols are easy to insert into a document on a PC with a numeric key pad; all the user needs to do is press the [ALT] key and key in the two or three digit numeric code.

I am well aware of the onerous method of inserting these characters into a WORD document by navigating through multiple menus and searching for the symbol needed. I am looking for a quick and simple way for inserting these ASCII characters (like the PC method of pressing [ALT] and then keying a three digit number code into the keypad). Is there a short cut in WORD for Mac for inserting the ASCII characters as described above? I am new to Mac and am hoping there is an efficient shortcut for inserting these ASCII symbols.