This first-grade math worksheet is an excellent way for students to practice addition within 100 using open number lines. The worksheet is presented on a single page and features four addition equations illustrated on number lines. Students will need to utilize the information displayed on the open number line to write and solve the corresponding equation. The number line jumps of tens and ones provide a valuable opportunity for students to gain experience in using open number lines to solve two-digit addition problems. For further targeted skills practice, similar worksheets titled "Open Number Line Addition Within 100: Write the Equation #2" and "Open Number Line Addition Within 100: Write the Equation #3" are available. Additionally, for related practice that allows students to complete the number line themselves, consider exploring "Adding Two-Digit Numbers on an Open Number Line #1."