Idiot\'s Guides Basic Math and Pre-Algebra

356 Idiot’s Guides: Basic Math and Pre-Algebra

reading

bar graphs, 264-265

circle graphs, 269-270

line graphs, 272-274

real numbers, 80

reciprocals, 62

rectangles, 184

rectangular prisms, 215

regular polygons

apothems, 195

area , 194 -196

relative frequency (probabilities),

253-254

relatively prime numbers, 53

remainders (division), 30

rhombus, 185-186

right angles, 156

right prisms, 216

right triangles, 172

30-60-90 right triangles,

176 -177

45- 45-90 triangles, 177

Pythagorean theorem, 173-175

Pythagorean triple, 175

trigonometric ratios, 240-244

cosine, 241-24 4

sine, 241-24 4

tangent, 241-24 4

Roman numerals, 4-5

rounding numbers, 11-12

rulers, 154

rules

division with variables,

106 -108

multiplying with variables, 105

S

scale factors (similar triangles),

236

scalene triangles, 170

R

radical form (square roots), 232

radius (circles), 198

range measurements, 283-284

rational numbers (fractions)

addition, 64-66

common fractions, 58

denominators, 58

division, 62-64

equivalent forms, 60-61

improper, 59

mixed numbers, 59

multiplication, 61-64

numerators, 58

proper, 59

simplifying, 61

subtraction, 64-66

ratios, 84

example problems, 86

extended, 85

measurements, 85

percentages, 88

changing to decimals, 92

changing to fractions, 92

example problems, 90-91

increases and decreases,

96-98

interest calculations, 92-94

tax calculations, 94-95

tip calculations, 95-96

proportions, 86

cross-multiplication, 87-88

example problems, 88

extremes, 86-88

means, 86

variables, 84

rays, 153

angles, 153-154

proportions, 86
cross-multiplication, 87-88
example problems, 88
extremes, 86
means, 86
ratios, 84
example problems, 86
extended, 85
measurements, 85
variables, 84
protractors, 155
pyramids, 219
surface area, 220-221
volume formulas, 221-222
Pythagorean theorem, 173-175
Pythagorean triple, 175

Q

quadrants (coordinate graphs), 135
quadrilaterals, 166
area formula, 188-191
parallelograms, 181-183
rectangles, 184
rhombus, 185-186
squares, 185-186
perimeters, 188
trapezoids, 186-187
isosceles, 187
medians, 187
quartiles
boxplots, 282-283
dividing data sets, 281-283
quick graphing techniques (linear
equations)
intercept-intercept method,
14 0 -141
y-intercept and slope method,
141-14 4
quotients (division), 28