6th grade addition up to hundred thousands Monster board game - Addition up to hundred thousands Monster Board Game - this is an interactive online game for 6th graders who would like to practice their mental math skills on a whole new level. This game keeps in mind the core standards of addition, and can help 6th grade students practice and perfect mental addition for numbers in the hundred thousand range. This game can also be used as a quiz or a test, as it offers students random various numbers that they will have to add mentally and pick the right answer. With this multiple choice trivia quiz students will be able to have a good time while they learn complex addition. Just watch out for the monsters, as they will take away all the points you have collected.