Too often we have a large amount of information to address in a short period of time, so we open the valve and let it flood the classroom. You know, think about what it would be like to drink from a fire hydrant. Class can't operate like that if you want to improve the students' understanding of the content. Instead, it is important to learn how to block and chunk time. This means that during planning you divide up the total amount of time into smaller chunks. You are focusing on the idea that their attention spans can only take about 10 to 15 minutes on one task, process, or activity. 20 minutes has to be your drop dead time frame. With the younger students you really have only a total of 10 minutes before you have to change the activity. Start using blocking or chunking. Your students will thank you and you will thank you.