Rounding and Formatting Numbers

    // round.js
    // Math.round( ), floor( ), ceil( ) – returns Number
    // Number.toFixed( ), to Exponential( ), toPrecision( ) – returns String
    // Number.parseInt( ), parseFloat( ) – returns Number
    //
    
    let number1 = 1111.567;
    let str1 = "1111.567 tonnes of apple sauce";
    let dec1 = 0.000161;
    
    Math.round(number1);	// returns to closest integer, 1112
    Math.floor(number1);	// returns to previous integer, 1111
    Math.ceil(number1);	    // returns to next integer, 1112
    
    number1.toFixed(4);	        // returns to 4 d.p., 1111.5670
    number1.toExpontential(2);	// returns to 1.11e+3
    number1.toExpontential(6);	// returns to 1.111567e+3
    dec1.toPrecision(1);	    // returns 0.0002 (looks at the first non-zero significant digit)
    
    parseInt(str1);	        // returns 1111
    parseFloat(str1);	    // returns 1111.567