NC.3.NBT.A Use place value to add and subtract.
NC.3.NBT.2 Add and subtract whole numbers up to and including 1,000.
NC.3.OA.D Solve two-step problems.
NC.3.OA.8 Solve two-step word problems using addition, subtraction, and multiplication, representing problems using equations with a symbol for the unknown number.
Your students can view and practice how to use bar diagram(s) to solve word problems with multiplication from the links below. Please scroll down to find the video(s) you need.