There are a quite a few ways in which to entertain a group of young children depending on their interests. Most children enjoy games, so you could find some age-appropriate board games and help them to understand the rules and play through the game. Alternatively, if you have space, you could have them play hide-and-go-seek indoors or outside, or alternatively games like 'suck in the mud' are fun for outdoor activity. For something quieter, you could find some rolls of butchers paper and drawing tools or paints and provide a theme for children to paint a mural together.