Turn your math worksheet into addition and subtraction cards
Printable sheets only cover the facts someone else picked. Upload your child's worksheet, class slides or notes and get flashcards with spaced repetition that match exactly what they are practicing.
Why custom cards beat a printed 0-20 sheet
Printable sheets of addition and subtraction flashcards 0-20 are easy to find, but they cover facts chosen by someone who never saw your child's lesson. A custom deck starts from the problems actually assigned, so practice lines up with homework and tests.
- Turns a photo of a worksheet into cards for the exact problems on it
- Covers sums and differences up to 20 with the number pairs your lesson uses
- Reschedules missed cards so tricky facts like 14 - 6 come back sooner
- Free plan includes 3 generations per month for trying your first deck
Built from your own material
Upload a PDF, slide deck, typed notes or a photo of a worksheet. The text is read and turned into cards for the facts on that page.
Spaced repetition
Cards you miss come back sooner, and the ones you know fade into longer gaps, so 0-20 facts stick without drilling the same sheet every day.
Study in the browser
The free plan lets you study on any device with a browser. Exports to PDF, DOCX, Anki and CSV are on the paid plans.
How it works
Upload the source
Add a PDF, DOCX, PPTX, text file or photo of the page with the addition and subtraction problems.
Generate flashcards
DeckOwl writes question-and-answer cards from the material, so each card matches a fact that appears in your own lesson.
Study and review
Work through the deck in the browser. Spaced repetition schedules the cards you find hard so practice stays short and focused.
Cards built from your own material also grow with the unit. When a new page of subtraction within 20 comes home, you can upload it and get a fresh set in minutes instead of searching for another worksheet.
Spaced repetition helps the facts move from counting on fingers to quick recall. Missed cards return more often, and mastered ones are shown less, which keeps a 10-minute session useful.
Explore related topics
Addition and subtraction flashcards 0 to 18
Make addition and subtraction flashcards for 0 to 18 from your own worksheets or notes.
Addition and Subtraction Flashcards to 20
Make addition and subtraction flashcards to 20 from your own worksheets or notes.
Addition and Subtraction Flashcards to 20
Custom addition and subtraction flashcards up to 20 from your own worksheet, made with AI.
Addition and Subtraction Flashcards
Make custom addition and subtraction cards within 20 from your own worksheets.
Addition Flash Cards 0-20 Custom Set
Custom addition flash cards for 0 to 20, built from your own worksheet. Study free in your browser.
Free Addition Flashcards 0 to 20
Turn your own addition notes into flashcards for 0 to 20, with spaced repetition.
Printable Addition Flash Cards 0 to 20
Make custom printable addition flashcards from your own sheets; PDF export is on Plus.
Addition and Subtraction Flash Cards to 20
Practice sums and differences within 20, generated from your own worksheets or notes.
Frequently asked questions
How many flashcards should a child practice for addition and subtraction within 20?
Most early learners do well with 15 to 25 cards per session, focusing on the number pairs they are still working out. Shorter daily sessions usually build recall better than one long drill.
Which 0-20 facts should come first in a flashcard deck?
Start with doubles like 6 + 6 and make-ten pairs like 8 + 2, then add subtraction facts that come from those same families. Your lesson or worksheet can tell you which families are being taught now.
Can I print the flashcards or export them?
The free plan lets you study in the browser without exports. Plus includes PDF, DOCX, Anki and CSV export, so you can print cards or move them into another app.
Do I need a credit card to try it?
No. You can start on the free plan without a credit card, and students with a school email get 40% off Plus.
Keep exploring the topic
Review the main ideas visually or practice recalling them.
Google Forms Quiz Responses Guide
Find, grade and export Google Forms quiz responses, or build new quizzes from notes.
Google Forms quiz generator
Draft quiz questions with explanations from your notes, ready to copy into a Google Form.
Science and Technology Mind Map PDF
Turn your own science and technology notes into an editable AI mind map.
Mind Map Border Ideas
Border styles for grouping and flagging ideas, plus a mind map built from your notes.