1 cube= 1 unit 1 Rod (Long)= 10 units 10 Rods (Longs)= 1 flat (1 flat=100 units) 10 flat =1 cube(1 cube=1000 units) 83×10= 830 2×10=20 830×20= 16,600 Just wanted to add more to help you understand why 83 is multiplied by ten and 2 is multiplied by 10. Its because when we use Base ten blocks, tens represent 1 Rod (Long)= 10 units. Hope it helps more.