The crowd was also played a video message from former England captain David Beckham.
After the Government committed to giving an extra £375 million to help feed the world's poorest children, Beckham said:
We've had good news. Earlier today the Prime Minister met with other world leaders and has made a real commitment to ending child malnutrition and hunger. There is more to do though and you can help.
More top news
The RSPCA has outlined in detail its policy on the shooting of seals that attack salmon stocks "as an absolute last resort".
We started the week warm, wet and windy but it will end much cooler and brighter.
The RSPCA is being criticised over its new welfare standards which permit salmon farmers to kill seals that attack fish stocks.