CCSS.Math.Content.1.NBT.C.5 1st Grade
Given a two-digit number, mentally find 10 more or 10 less than the number, without having to count; explain the reasoning used.
Practice CCSS.Math.Content.1.NBT.C.5 Given a two-digit number, mentally find 10 more or 10 less than the number, without having to count; explain the reasoning used.
