These addition and subtraction problems probably aren't written the way your scholars are used to seeing them, especially since they have double-digit addends and subtrahends. This set of eight horizontal equations gives learners a chance to practice their mental math skills, applying place-value knowledge to complete each number sentence. Because the answers are listed on the right, encourage kids to add (or subtract) the tens first, find possible options on the right, then include the ones to determine the answer.