Check this again at the end of the day. Ask the children once again for predictions. Write the actual value on the board and leave it there for the next day to help their predictions. Start a concept map bulletin board. Start with a few words like population, growth, birth rate etc.
Every morning ask the students to add any new words from the day before.
Help them to show how things are linked. This serves as a review of the day before, also as an evaluation of how well you are getting the information across to the students. Start at the beginning and move towards modern times. Each talk may last around one hour. Discuss with the class the subject of increasing food availability.