IGCSE›Cambridge IGCSE Maths›Mind mapsNumber ToolkitCambridge IGCSE Maths: Mind mapStudy pack PDFAlso for this subtopic:Revision notesFlashcardsSubtopic testCover factsNumber typesNatural: positive counting numbers 1, 2, 3Integers: whole numbers including zero and negativesPrime: exactly two factors, 1 and itselfRational: writes as a fraction ab\frac{a}{b}baIrrational: no exact fraction, e.g. 2\sqrt{2}2Reciprocal of 5 is 15\frac{1}{5}51Words and figuresGroups of three: thousand, million, billionSix billion = 6 000 000 000Use zeros as placeholders for empty groupsNumber toolkittypes and operationsℕℤℚπ\piπFour operationsBIDMAS: brackets, indices, division/multiplication, add/subtract5−(−3)=5+3=85 - (-3) = 5 + 3 = 85−(−3)=5+3=8Two negatives multiplied give a positiveOne negative, one positive gives a negativeConvert mixed numbers to improper fractions firstRecall by heartSquares 1 to 15 (1 to 225)Cubes of 1, 2, 3, 4, 5 and 10Cubes: 1, 8, 27, 64, 125, 1000Know the matching square and cube rootsExam tips3+4×2=113 + 4 \times 2 = 113+4×2=11, not 14Recalling squares saves time on the non-calculator paperReread the context: is the sign sensible?