function roundDownToNearest10(num) {
return Math.floor(num / 10) * 10;
}
console.log(roundDownToNearest10(73));
console.log(roundDownToNearest10(89));
console.log(roundDownToNearest10(999.99));
console.log(roundDownToNearest10(9.197));
console.log(roundDownToNearest10(6));
console.log(roundDownToNearest10(16));
console.log(roundDownToNearest10(-18));
console.log(roundDownToNearest10(-103));
console.log(roundDownToNearest10(-109));
/*
run:
70
80
990
0
0
10
-20
-110
-110
*/