\sum\limits_{k = 1}^n {k^2 = \frac{{n\left( {n + 1} \right)\left( {2n + 1} \right)}}{6}}
% MathType!MTEF!2!1!+- % feaafaart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqr1ngB % PrgifHhDYfgasaacH8YjY-vipgYlh9vqqj-hEeeu0xXdbba9frFj0- % OqFfea0dXdd9vqai-hGuQ8kuc9pgc9q8qqaq-dir-f0-yqaiVgFr0x % fr-xfr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaaabCae % aacaWGRbWaaWbaaSqabeaacaaIYaaaaOGaeyypa0ZaaSaaaeaacaWG % UbWaaeWaaeaacaWGUbGaey4kaSIaaGymaaGaayjkaiaawMcaamaabm % aabaGaaGOmaiaad6gacqGHRaWkcaaIXaaacaGLOaGaayzkaaaabaGa % aGOnaaaaaSqaaiaadUgacqGH9aqpcaaIXaaabaGaamOBaaqdcqGHri % s5aaaa!4B15!
Pasting the above "text" into MathType 5.0 will enter the above equation and make it possible to edit, save, and use in applications such as MS Word.