Kindergarten ABC worksheets should have different activities to help children identify the various letters of the alphabet. The activities may involve very simple things like colouring, ticking, drawing a line to match items etc. Using attractive illustrations and cartoon characters would make it more fun for children. The activities should be graded, i.e initial activities should be very simple and easy (but should be fun with good pictures etc, so as to interest the child); later worksheets may involve a little bit more work.
Math concepts can also be reinforced for the children throughout the day on a regular basis. Try placing an enlarged number 12 above the 12 on the clock and label it "lunch time". Label your clock with as many of these types of labels that you can. This will help the children to recognize the way the clock looks when it is on the hour. Make sure to point out the clock when it is time for lunch by saying, "Look at the clock, it is time for lunch. See the little hand is on the 12". You can also incorporate math through songs. If you are learning about monkeys, make it a point to sing, "Five Little Monkeys Jumping on the Bed". The same concept can also be used when you are reading books to preschoolers. There are plenty of books that incorporate counting into their story and will follow the theme you are teaching. Math is a concept that children will have to use for the rest of their lives and that will be continuously taught in school. By starting off their education with fun math activities, you can get them started with math the right way.