In this worksheet, you must work out what went in or what comes out of a Doubling Machine.
Here 6 x 2 = 12, so when 6 goes in, 12 comes out.
Also 12 ÷ 2 = 6, so when 12 comes out, 6 must have gone in.
Remember that...
Doubling is the same as multiplying by 2.
Halving is the same as dividing by 2.