64 rounded to the nearest tens place is 60.
245 to the nearest tens place is 250
159.444 to the nearest tens place = 160
395 to the nearest tens place = 400
923 to the nearest tens place = 920
8,146 to the nearest tens place = 8,150
542 to the nearest tens place = 540
394 to the nearest tens place = 390
5,253 to the nearest tens place = 5,250
103 to the nearest tens place = 100
6,512,162 to the nearest tens place = 6,512,160
5,465 to the nearest tens place = 5,470