David and Jillian are playing a board game together. Jillian wants to trade her wool cards for David's ore cards. The double number line shows that David will trade \[3\] ore cards to Jillian for \[6\] wool cards. A double number line with 6 equally spaced tick marks. The line labeled Ore cards, reads from left to right: 0, two unlabeled tick marks, 3, two unlabeled tick marks. The line labeled Wool cards, reads from left to right: 0, two unlabeled tick marks, 6, two unlabeled tick marks. \[0\] \[3\] \[3\] \[0\] \[6\] \[6\] Based on the ratio shown in the double number line, how many wool cards does Jillian need to trade for \[4\] ore cards?