Since this week's learning project is themed around the sea, it would be a brilliant way to introduce your children to capacity. I have included a brilliant guided lesson plan from Nrich to help explore capacity at home in addition to some picture prompts for more ideas. Using language of more, less, full, empty, thinner, taller, holds more/less etc will be so valuable to expanding your child's knowledge of different measures. Another way of introducing this would be to say that one of your family members is really thirsty and challenge your child to figure out which out of multiple containers would hold the most water. They can make predictions, test their ideas, say what they found out at the end and discuss whether their predictions were correct after all! Have fun!