Algebraic marks

A knowledge of the proper meaning of these can only be acquired by the study of mathematics, but the following statement of the names of them will be useful to reading-boys and others who are required to pronounce them:—

• + plus
• ÷ division
• ∴ therefore
• ° degree
• − minus
• = equal
• :: so is
• ∥ parallel
• √ root
• × by (multiplication)
• : to (in proportion)
• ′ minute, ″ second