We took 4 (ages 11, 10, 8 & 6) to Europe for 4 months.

Not a problem at all with them being away. When they got back they were leaps and bounds ahead of a lot of their classmates in subjects such as english (we were teaching them simple phrases in local languages, so they were learning about sentence structure & what words were verbs etc), geography, art, history, even maths (exchange rates etc). They also had schoolwork supplied by their teachers. I love travelling with young ones, just their wonder when they see something new.