One of my fellow contributors here recently wrote a post about leap years and why we have them. This reminded me of modular arithmetic and the formula for calculating the day of the week for any ...

Asha K. Jitendra, Danielle N. Dupuis, Anne F. Zaslofsky, Curriculum-Based Measurement and Standards-Based Mathematics: Monitoring the Arithmetic Word Problem-Solving Performance of Third-Grade ...

Ravi S. Kulkarni, An Arithmetic-Geometric Method in the Study of the Subgroups of the Modular Group, American Journal of Mathematics, Vol. 113, No. 6 (Dec., 1991), pp. 1053-1133 ...