Missing Addend Games Online Free
Find the missing number in an addition sum, like 8 + □ = 13 or □ + 6 = 15. Every total is 20 or less.
Type answers on your keyboard, or tap the number pad.
Practise these again:
What is a missing addend?
An addend is a number being added. In a missing addend problem, one of them is hidden: 8 + □ = 13. You know the total, so you work out what was added.
It’s really subtraction in disguise. 8 + □ = 13 is the same as 13 − 8 = □. Children who find these hard can build up with number bonds to 20 first.
How to play Missing Addend
- Choose the 60-second challenge or untimed practice, then press Start.
- Type each answer on your keyboard or tap the number pad. It’s checked as soon as you’ve typed enough digits, or press ✓.
- Get one wrong and you’ll see the right answer, and the question comes back a little later.
- At the end, check your score and the facts to practise again.
Missing Addend skills
- Finding a missing addend within 20
- Linking addition and subtraction
- Counting up from one number to another
Level: Grades 1–2 (ages 6–8)
Tips for missing addends
Count up from the number you know: for 8 + □ = 13, count 9, 10, 11, 12, 13. That’s 5.
Go through ten: 8 + 2 = 10, then 3 more makes 13. 2 + 3 = 5.
Use subtraction: 13 − 8 = 5.
Missing Addend questions and answers
Is this the same as a missing number game?
Yes. Missing addend is the math name for a missing number in an addition sum. All the questions here are within 20.
Why do children find missing addends hard?
Many children see “+” and add the two numbers they can see (8 + 13). Saying the question out loud helps: “8 and what make 13?”
What grade learns missing addends?
US first graders solve missing addends within 20, and second graders continue with them as part of fluency within 20.