There are some new materials being developed now based on what we are learning about how the brain learns. These brain_friendly materials should be an improvement over what has existed. I recently bought a book by Marcia L. Tate titled "Mathematics Worksheets Don't Grow Dendrites." I highly recommend her book. She gives a great deal of information on alternative activities that are better for your child's brain development and for learning.
Use heart_shaped candy to teach the more simple mathematical arithmetic; like addition and subtraction. Provide children with pre_determined math problems that they can figure out using the sweets. Alternatively, make heart_shaped numeral cards that children can arrange on their desk to solve a math problem. You could give them a total to reach and they must use the cards to create the question. There are websites that offer a vast array of Valentine's Day worksheets. They offer varying levels of difficulty to make them suitable for Grade One to Grade Five. Each set of math worksheets include all the major mathematical problems; addition, subtraction, multiplication, division and even word problems. All these sheets include Valentine's Day pictures. The online math worksheets are also available with pre_written word problems that are all associated with what happens on Valentine's Day.