# This set of numbers is denoted $\mathbb{N}$: 1- 2- 3- … ---- ## The natural /ˈnætʃrəl/ numbers --- # This set of numbers is denoted $\mathbb{W}$: 0- 1- 2- 3- … ---- ## The whole /həʊl/ numbers --- # This set of numbers is denoted $\mathbb{Z}$ - Un entier relatif ---- ## An integer /ˈɪntɪdʒə[r]/ --- # This set of numbers is denoted $\mathbb{D}$, A number which can be written as $\dfrac{a}{10^n}$ with $a\in\mathbb{Z} and $n\in\mathbb{N}$ ---- ## A decimal /ˈdesɪml/ number --- # This set of numbers is denoted $\mathbb{Q}$, Un nombre rationnel ---- ## A rational number --- # This set of numbers is denoted $\mathbb{R}\backslash\mathbb{Q}$, Un irrationnel ---- ## An irrational number --- # This set of numbers is denoted $\mathbb{R}$, Un nombre réel ---- ## A real number --- # A number composed of a positive integer and a fraction less than 1. Ex: $2\frac{2}{3}$ which means $2+\frac{2}{3}$ and would be read two and two thirds ---- ## A mixed number --- # $]-\infty;0]$ ---- ## $(-\infty-0]$ --- # $]-10;10[$ ---- ## $(-10-10)$ --- # Ces deux intervalles ne se chevauchent pas ---- ## There is no overlap between these two intervals --- # A number or an expression which contains an irrational root (e.g. square root or cube root)- i.e. that cannot be expressed as a rational number ---- ## A surd /sɜː[r]d/ --- # A compound /ˈkɒmpaʊnd/ surd ---- ## A surd in the form $2+\sqrt{3}$ --- # If $a+\sqrt{b}$ is a compound surd, then its conjugate /ˈkɒndʒəɡeɪt/ surd is ---- ## $a-\sqrt{b}$ --- # To remove the surds from the denominator of a ratio ---- ## To rationalise /ˈræʃnəlaɪz/ a denominator /dɪˈnɒmɪneɪtə[r]/ <style> .slides {background-image:url("https://raw.githubusercontent.com/tremulotmaths/latex/master/von_koch_transparent.png");} .slides h1 {padding:2em; font-family:Arial; background-color:#133E29; opacity: 0.9;color:white; font-size:1em!important;} .slides h2 {background:#131750 ; opacity: 0.9;padding : 2em 0.2em; color:white; font-size:1em!important;} .slides h4 {margin-bottom:1.5em} </style>