Get this resource as part of our great value Crossnumber Bundle! Engage your students with this crossnumber on finding and using upper and lower bounds. Students solve the interleaved questions and use their answers to complete the crossnumber. Extend the thinking of those who complete the questions by getting them to write a new set of questions - a considerable skill! Full instructions, ideas for support, and a solution are provided in the resource - what more could you need? Try a resource like this for free!