A mnemonic for remembering the priorities with which a calculation should be determined. BIDMAS stands for brackets, indices, division-multiplication, addition-subtraction. BODMAS is alternatively used with ‘orders’ replacing ‘indices’. So 2 + 3×4 = 14 as the multiplication is done before addition. Note that division and multiplication have equal priority, likewise addition and subtraction, despite the order the letters appear in the acronym. So 2−3 + 3 = 2 rather than −4 (which would be the answer if addition preceded subtraction).