Goodmayes youngsters have picked up rubbish in the community.
Reception pupils at Farnham Green Primary School also enjoyed a virtual tour around a recycling plant and set up their own recycling centre.
Teacher Amy Hoang, from Romford, said: "The children were so enthusiastic about our topic - of The Blue Planet - that they were coming up with ways we could help.
“It is a project we have all enjoyed and will continue in the future."
Pupil Nylah Richards said: "I love looking after the planet and when we did litter picking, we helped to tidy up the mess.
“I liked going out with my friends, we even saw a squirrel.”
Classmate Ibad Rizwan added: "We have to take care of the planet, I loved going out and cleaning up outside."
Headteacher Angela Maber said: “It is important that we encourage the children of Farnham Green to look after the planet and our youngest children made us very proud when they came up with the idea to go litter picking this week."
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