A great resource that my colleague and I completed over a 1/2 term in the afternoon lessons to build a car out of wood and plastic - wheels parts etc we bought off EBay and YPO catalog for the children who completed one between 2 - this used their maths skills, construction skills and science forces skills as they have to build an elastic band powered car that would hold a 1kg weight and travel down the school corridor - It went really well as a project that we ran for 2 different year groups.
This would work for early secondary school DT also and is a great cross curricular lesson and activity - any questions do ask away !