Problem solving weight with science space topic

I designed and used this problem solving activity with a LA Year 5 group, but can be easily adjusted by changing the values of the weights. The chn had to use division skills to convert 'Earth kg&' into &';Space kg'. They then had to use their addition skills to find all of the combinations of items they could take with them on their journey, but they must meet a set criteria. The EXT then called for them to have to work out the inverse calculation to convert items found from &'Space kg&'; to 'Earth kg&'. The chn loved this and it kept them very busy for two lessons.