Mathematics is a common component of many science and social science degrees, but frequently not considered a prerequisite for their study. This can lead to some students studying mathematics components at undergraduate level with little or no previous mathematical learning and varying levels of motivation, or desire, to study mathematics. This situation has consequences for student experience and teaching practice, including the potential for lower levels of student engagement, higher levels of student anxiety and lack of student motivation for studying a subject that is not what they chose as their degree subject. This paper details an intervention designed to address issues experienced in the teaching of mathematics to undergraduate students, with varying motivation for the study of mathematics and high levels of mathematics anxiety, in their first year of study in a department of Earth Sciences at a UK university. The intervention provided a bespoke mathematics module, designed and taught collaboratively by a teaching specialist in mathematics and a subject specialist in Earth Sciences. The mathematics specialist was able to provide extensive experience in teaching students from widening participation backgrounds and those with mathematics anxiety, making the content more accessible to the students, particularly those with mathematics anxiety. The Earth Sciences specialist was able to contextualize the mathematics content, showing students how the content was applicable to the rest of the degree and helping locate the mathematical content within the broader scope of the discipline. Previous approaches to this module were taught either solely by an Earth Sciences specialist or solely by a mathematics specialist. Compared with those approaches the collaborative teaching intervention improved student attainment by 10% in the average module mark and moved the module from having the lowest student satisfaction scores in the department to the highest. This innovation also benefited both teachers with respect to professional development, which is discussed in the paper.