Hi Alexis,
 
At a U.S. public school, a teacher would need to consider that his/her students may come from multiple religious backgrounds. The U.S. Constitution grants religious freedom, and not every student is a Christian. So teaching values labeled as Christian during a math lesson could potentially infringe upon the rights of (and make uncomfortable) the atheists, Jews, Muslims, Buddhists and other students in the classroom who aren't Christian.
 
As a parent of a child in such a classroom, I'd request from the teacher more information about how the Christian religion pertains to the facts of the math lessons, and how that teaching would help my student learn basic math facts and meet state standards for math skills. Unless associated with a numerical word problem or statistical analysis, the examples you gave sound more like life skills lessons, and could apply to values across multiple religions (not just the Christian faith).
 
To focus on Christianity in your lessons, you might consider teaching math at a Catholic private school or a Christian institution where parents and students can expect the Christian faith to be incorporated into the curriculum.    
 
Thanks for asking this interesting question! Below are some additional resources you may find informative as well.