Adding and Subtracting 2-Digit Numbers Logic Puzzles for February and Valetines. Perfect for practicing adding and subtracting groups of 10, making groups of 10 to add on, place value, missing addends/subtrahends. These Valentines-themed puzzlers are ideal for math enrichment and challenge! So often it seems that finding just-right resources for all of our learners is a full time job, especially for our highest group of mathematicians. These are the friends working a grade-level (or two) above 1