function roundDownToNearest10(num : number) : number {
return Math.round(num / 10) * 10;
}
console.log(roundDownToNearest10(22));
console.log(roundDownToNearest10(79));
console.log(roundDownToNearest10(71));
console.log(roundDownToNearest10(39.99));
console.log(roundDownToNearest10(55.17));
console.log(roundDownToNearest10(3));
console.log(roundDownToNearest10(18));
console.log(roundDownToNearest10(-14));
console.log(roundDownToNearest10(-101));
console.log(roundDownToNearest10(-109));
/*
run:
20
80
70
40
60
0
20
-10
-100
-110
*/