My son recently turned 5 at the end of January. He has been in preschool full-time since the age of 2. He is currently working on reading and they began having spelling tests when he turned 4. He knows his continents, address, phone number, president, capitols, bodies of water, colors, planets, sign language, he can count and greet in Spanish, he can count by 2's 5's and 10's (up to 100), tell time, his class has just recently begun learning how to add and he has a very extensive vocabulary. Because his school offers art as a subject, he knows how to use scissors, paint neatly and colors very well. He writes extremely well for his age (according to his teacher) including his name, numbers and random words for spelling tests. Science, music and computers are subjects as well, so he is knowledgeable regading instruments, the internet (for kid sites) and basic life science. He goes to a small school so I think there may be about 8-9 children in his class. He has homework packets every week, thatnormally consists of reinforcing whatever they learned for the week (spelling words, fill in the blanks for time...etc.)
I hope this helps, it was a little long, but I just wanted to make sure that I provided enough detail. Both of my boys attend a Montessori, so it may depend on the curriculum being offered at your children's school.