We were on a mission this afternoon to find items that balanced either a 10g, a 100g or a 1kg weight. We found lots of items that weighed the same as the 10g, including toy fish, a felt-tip pen and a wooden letter. We found nothing that weighed the same as 100g or 1kg, until William cleverly realised that 10 individual 100g weights balanced with the 1kg! Such active maths detectives!