In England, the national primary school curriculum is divided into segments called Key Stages. Key Stage 1 includes children aged five to seven, and is equivalent to first and second grade in the United States. In England, many schools hold whole-school assemblies daily or weekly. This is a way to build school spirit while meeting statutory requirements to provide acts of collective worship and promote social and emotional aspects of learning. Almost anything can be turned into an assembly, and there are an endless number of ideas for assemblies.
You can bring assemblies to life and involve more students by using drama. Write up a script on a given topic, such as healthy eating or an upcoming holiday, and assign roles to students in your class. You could also have younger Key Stage 1 students act out a story as you read. Students can put on a puppet show and make the puppets beforehand as part of an art lesson. Older Key Stage 1 students might enjoy writing their own simple scripts, and younger Key Stage 1 children might enjoy performing songs they have learnt in class.
Younger students in Key Stage 1 study different types of changes, and this can make a good topic for an assembly. Students can demonstrate changes that occur all around us -- such as ice melting, bread turning brown and crisp when it is toasted and baking soda and vinegar foaming when mixed together. They could also discuss the changes that occur with the seasons and dress up as different seasons. At the end of the assembly, they could invite older children and teachers on stage to see the changes that people go through as they get older.
Cooperation is an important topic in Key Stage 1 and students could put on a simple play to demonstrate cooperation. Students could tell the story of two greedy brothers who did not get along and never helped each other. As punishment, the king locked them in a room with large piles of food, but they could only eat using a yard-long spoon which they could only hold by the very end. Children could tape spoons to yard sticks to use as props. The two brothers eventually learnt to cooperate and feed each other with the spoons. End the assembly by having the children discuss the importance of always working together to solve problems.
Schools in England are required to teach about five major world religions as part of the school curriculum. Most primary schools hold assemblies to mark major religious festivals such as Easter, Diwali, Passover and Ramadan. Your Key Stage 1 students could organise an assembly about holidays. Students from different backgrounds could describe how they celebrate different holidays in their homes or communities. Or, the assembly could focus on only one holiday, such as Christmas, and each child could give one or two sentences about how the holiday is celebrated in different countries around the world.