The Williams Review (Dept. for Children, Schools and Families, 2008) is significantly important to all early years and primary educationalists, including those who are involved in teaching mathematics to the next generation of primary school teachers. The report, compiled as a result of this review, sets out the ways that children in primary schools and early years settings can most effectively gain an understanding and appreciation of mathematics. As a maths tutor on a primary Postgraduate Certificate in Education (PGCE) course, this author is clearly one who needs to begin to implement the recommendations of this major review into the teaching of mathematics. In order to determine how prepared the new generation of teachers are, Davis conducted a small-scale study designed to answer the following questions: (1) What mental calculation strategies do the students possess?; (2) Can my intervention enable the students to learn a range of mental strategies and use them effectively?; (3) Is there any effect of the intervention on classroom practice?; and (4) Are the students more confident in their own abilities to teach a range of strategies after intervention? Results of this study indicated that just a small amount of input for initial teacher training students can have a large impact on their understanding, knowledge, and ability to focus on key strategies in school. (Contains 5 figures.)