Review: Add and subtract within 20
Add the numbers.
Add the numbers.
Print worksheets and answer keys · A4 / Letter
Grade 1 Review for Addition Within 100 gives students focused practice connected to Common Core 1.NBT.C.4. Students add a two-digit number and a one-digit number while keeping each total at 100 or less. The worksheet opens with a fresh set of problems and includes an answer key generated from those exact numbers.
This review uses the prerequisite generator already linked to the topic. It is a practical warm-up before students begin the grade-level work. Separate tens and ones, make a new ten when helpful, and check that the answer is reasonable. Ask the learner to explain one answer aloud; a short explanation often reveals whether the place-value or fact strategy is understood.
Select New numbers to create another set without changing the skill. Use the Worksheet and Answer key controls to preview either page. The print choices can include the worksheet, the answer key, or both. The same seed is used for both versions, so every problem stays in the same position. Printing is free and works on US Letter and A4 paper.
This page is focused practice for one arithmetic objective rather than a complete assessment of the standard. Start with accuracy, use a drawing or place-value model when needed, and move to a fresh set after the learner can describe the method independently.