You could do this with my picture method, though it's a little more awkward to draw. Make a bar representing x (with two parts), and cross off half of it (or otherwise mark it as removed. What's left, one piece, is 3; x is two of those pieces, i.e. 6.

Code:

```
+-------+-------+
| x |
+-------+XXXXXXX+
\_______/
3
```

But I think it's easier to use the method (equivalent to the algebra) commonly used to teach prealgebra students to solve percent increase or decrease problems. Think of your problem as this: An item is on sale at 1/2 off, and now costs $3. How much does it normally cost?

Taking half off means that the amount you are paying is 1 - 1/2 = 1/2 of the original; if 1/2 of the original is 3, then the original is twice that, 6.

In percentage problems, we would say that 20% off means paying 80%, so you divide by 80% to find the original price.

As you can see, the work is exactly what you would do in algebra, but the thinking doesn't require willingness to do algebra, much less knowledge of it.