BACHMANNTrains - Snap-Fit E-Z TRACK 11.25” RADIUS CURVED TRACK (6/card) - NICKEL SILVER Rail With Grey Roadbed - N Scale, 8

Q: how many needed to make an oval?

The answer of 8 pieces was wrong. These are 30 degree curve sections. In other words, it takes three of these to change your train's direction 90 degrees, six to go 180, and 12 to make a full circle, 360 degrees. To make an oval, you would need 12 of these curve pieces, plus 2 or 4 or 6 (whatever) straight pieces, so it is inded an oval and not a perfect circle. Hope this helps.