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Adding Two-Digit Numbers Within 100

1st Grade · Math · Open Global Math

9 lessons

Goal

Add within 100 using concrete models, number lines, place-value strategies, and expanded column methods, composing a ten when needed.

9 lessons
0 of 9 done
  1. Adding Tens to a Two-Digit Number with Base 10Up next
  2. Adding Multiples of Ten on an Open Number LineNot started yet
  3. Adding a Two-Digit Number and a One-Digit Number Without RegroupingYou are here
  4. Adding a Two-Digit Number and a One-Digit Number by Making a TenNot started yet
  5. Adding Two-Digit Numbers: Adding Tens to Tens and Ones to OnesNot started yet
  6. Adding Two-Digit Numbers on an Open Number LineNot started yet
  7. Adding Two-Digit Numbers with Regrouping Using ModelsNot started yet
  8. Adding Two-Digit Numbers Using Expanded Column AdditionNot started yet
  9. Solving Addition Word Problems Within 100Not started yet
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Learning standards covered

GlobalOGM.2.NBT.4Open Global Math Standards 2026™ · 1st Grade

Add within 100, including adding a two-digit number and a one-digit number, and adding a two-digit number and a multiple of 10 (or multiple of 10 and 1-digit number), using concrete materials, open number lines, place value strategies, and written column/expanded methods; understand that tens are added to tens, ones to ones, and compose a ten when necessary.