how to put mathematical symbols in html code example

Example: html mathematical symbols

CHAR	NUMBER		ENTITY		DESCRIPTION
∀		∀		∀	For all
∂		∂		∂		Partial diffrential
∃		∃		∃		The exists
∅		∅		∅		Empty sets
∇		∇		∇		Nabla
∈		∈		∈		Element of
∉		∉		∉		Not an element of
∋		∋		∋		Contains a member
∏		∏		∏		N-ary product
∑		∑		∑		N-ary summation