let simpleNumber = 12 //simple number

Numbers in JS are represented with 64 bits for each one. That means 2e64 different numbers, that is 18, 000 000 000, 000 000 000.

Pero dependiendo del número se usará una cantidad de bits para almacenarlo.

let factionalNumber = 9.81
let veryBigNumber = 2.998e8 // 2.998 * 10e8 == 299,800,000

Aritmethics

// the presedence is equal than mathematics
let leftToTight = 100 + 4 - 11
let multiplyAndDivideFirst = 100 + 4 * 11
let parenthesesFirst = (100 + 4) * 11

// when you're creating operation be sure about spaces
20 --2                  // Error Syntax
20 -2                   // 18
20 - -2                 // 22

Special Numbers

let infinito = Infinity            // number - trully
let infinitoNegativo = -Infinity   // number - trully
let notANumber = NaN               // number - falsy
let quotedNumber = '200'           // string - trully

(infinito - 1 === infinite)        // infinito menos 1 sigue siendo infinito
(0 / 0 === NaN)                    // 0 / 0 da igual a NaN
(infinito - infinito === NaN)      // da igual a que no es un numero

Operators in numbers

// simple opertors
10 + 1 // 11
10 - 1 // 9
10 / 3 // 3.3333333
10 % 3 // 1
10 * 3 // 30

// special operators
let data = 2

data += 2 // data = data + 2
data -= 2 // data = data - 2
data /= 2 // data = data / 2
data %= 2 // data = data % 2
data *= 2 // data = data * 2

data++ // add 1 after this row
++data // add 1 in this row
data-- // rest 1 after this row
--data // rest 1 in this row

10 == 10 // true, checks only value
10 === 10 // true, checks value and type