The wires should be about 5" long for one strip, and about 10" long for the other. We can trim them down later, so when guesstimating lengths, always err on the side of "too long".
We'll call the one with shorter wires strip #1, and the one with longer wires strip #2.
If all your connections are good, the strips will light up when you plug in your battery and tilt the Circuit Playground. Let's secure the ends of the strips so they don't ever pull out or break while you're wearing the ears.