Link to online lesson
https://whiterosemaths.com/homelearning/year-3/
Videos that could help
https://www.youtube.com/watch?v=mO53rHEIQr4 - adding fractions
https://www.youtube.com/watch?v=mO53rHEIQr4 - subtracting fractions
Challenge videos
https://www.youtube.com/watch?v=tDQipFjAoT8&list=RDCMUCW5diHfMyIPW3XNFzh4-1SA&index=2 - adding fractions with different denominators.