Have your students gotten stuck using just one, often inefficient strategy? Do they lack solid reasoning skills? Are you looking for a way to encourage students to make connections to develop and use new strategies? Problem Strings are an instructional routine that can boost number sense and mathematical reasoning skills by teaching students how to make and use connections to develop and practice new strategies. Problem Strings can stretch students beyond their comfort zones in discourse-rich minilessons that encourage them to use what they know to solve problems in sophisticated ways.