Kids are ready for formal operations when their earlier experience has prepared them for formal operations. In some places around the world, students in fifth grade--including below-average fifth-graders--are already learning algebra. In quite a few whole countries around the world (for example, Taiwan, where my wife grew up when Taiwan was still a developing country) all seventh graders study algebra and geometry as part of their regular school math lessons, yes, including the below-average seventh graders. (In Taiwan, they also learned enough of the International Phonetic Alphabet to transcribe General American English at that age, but now that skill, which most United States reading teachers lack entirely even with a college degree, has moved into the elementary school curriculum.) Good education at the beginning produces better results in the middle grades.[1]<p>[1] <a href="http:&#x2F;&#x2F;www.amazon.com&#x2F;Knowing-Teaching-Elementary-Mathematics-Understanding&#x2F;dp&#x2F;0415873843" rel="nofollow">http:&#x2F;&#x2F;www.amazon.com&#x2F;Knowing-Teaching-Elementary-Mathematic...</a><p><a href="http:&#x2F;&#x2F;condor.depaul.edu&#x2F;sepp&#x2F;mat660&#x2F;Askey.pdf" rel="nofollow">http:&#x2F;&#x2F;condor.depaul.edu&#x2F;sepp&#x2F;mat660&#x2F;Askey.pdf</a><p><a href="http:&#x2F;&#x2F;www.ams.org&#x2F;notices&#x2F;199908&#x2F;rev-howe.pdf" rel="nofollow">http:&#x2F;&#x2F;www.ams.org&#x2F;notices&#x2F;199908&#x2F;rev-howe.pdf</a>