Hi, sharon.

Right now, Level F is on the 'drawing board'. There will be a Level F, but its exact contents have yet to be released.

That being said, I do know that some of the Levels (particularly Level C) are very large and so one of the intentions for the rewrite is to 'spread out' the lessons slightly. However, in each Level that is being rewritten - lots of new information is being included. For example, in Level A 2nd Edition, Dr. Cotter has included weights, measurements - both centimeters and inches, more geometry, etc. So, I think it is fair to say that the Second Edition Level F will contain more information/teaching than just 'spreading out' the levels.

That being said, I have taught the First Edition to 3 of my kids. However, this year I am purchasing the 2nd Edition for my final child. It is worth it for me after I have looked through Level A.

I hope that helps!
If you have any further questions, feel free to post here. Or you can email me directly at rachel@rightstartmath.com.

Have a great day!
Rachel