1. Show a video clip or have students research the most important inventions of the past 100 years, which also has a history tie.
2."100 licks" is a lab I did a while ago! The kids love it, but it's sticky. Split kids up into groups of 4, or however many lollipop types you have. Which lollipop can disappear in 100 licks? Students track with pictures, drawings, or weight the difference after every 10 licks. I show the old tootsie pop clip.
3.If you have static electricity tie in, give each of the groups a balloon and wool cloth. Then student record how many items (small pieces of torn paper or rice crisps) the balloon will pick up after every 10 rubs on the balloon until they hit 100. Then they analyze at what point rubbing no longer makes a difference.
4. There is a great biology site that times out how many cells form and die. You can track how long for different types of cells to reach 100, or how many form/die in 100 seconds. http://www.centreofthecell.org/interactives/cellturnover/index.php
5. Visit 100 greatest discoveries of all time...
6. 100 illustrated science vocabulary words (about 4 words each). To create a kid generated visual word wall.
7. You might also check some other blogs...This is from the science website I created for my staff. It is a list of blogs that have a focus on science broken down by different grade level and specialty. http://sites.google.com/site/spectacularsensationalscience/teacher-resources/science-blog