Monkey Business Adding with an Unknown Number Activity
This monkey business adding with an unknown number activity helps 1st-2nd grade students find missing addends within 20 by matching cards. Answer key included for fast checking.
$6.97
Want this one free?
Tell us where to send it and it’s yours — no card, no catch.
One free resource per teacher. We’ll also send free teaching ideas each week — unsubscribe anytime.
Free teacher account · no credit card
Membership
Get every game, song, & printable
- Every game, on any device
- 6,500+ resources
- Assign online with HFT Classroom
Then $39.97/year · cancel anytime · See plans
- Instant digital download
- Printable PDF + answer key
- Made by real teachers
Teacher / Family membership
Teaching is easier with every resource
One membership for your whole year: 6,500+ worksheets, games, songs and videos for Preschool–6th, for your classroom or homeschool.
- Unlimited printables & downloads
- Every game, on any device
- Assign online with HFT Classroom
- Cancel anytime
Teacher / Family membership · 3 days free
Yearly
Monthly would be $119.64 a year
$3.33/month
Billed $39.97 once a year
You save $79.67 every year
Start My 3 Free Days$0 today · cancel anytime
Monthly
$9.97/month
Flexible, month to month
Yearly is just $3.33/mo. Switch and save $79.67
Start My 3 Free Days$0 today · cancel anytime
About this resource
Description
How to Teach Finding the Missing Addend
This monkey business adding with an unknown number activity gives first graders a fun way to find the missing number in an addition equation. In an equation like 8 + ? = 13, students think about what they can add to 8 to make 13. Some equations put the unknown first, and some put the equal sign on the left side, so children learn that the equal sign means both sides have the same value. These skills build strong addition and subtraction facts within 20.
About the Activity
Students lay the banana answer cards face up, pick a lettered equation card, and find the banana card with the number that makes the equation true. Every answer is different, so each equation card matches exactly one banana card. Students record each answer on the Recording Sheet, then finish a practice worksheet with eight new missing addend equations. Use it in a math center, with partners, in a small group, or as a whole class warm-up. It also works well as a missing addend game for review in second grade.
What’s Included
- Colorful activity cover
- How to Use page with prep tips and simple steps
- 12 lettered equation cards
- 12 banana answer cards
- Recording Sheet
- 1st grade practice worksheet with 8 equations
- Answer keys for the Recording Sheet and the practice worksheet
Why It Helps Kids
First, finding a missing addend helps children see how addition and subtraction are related, which makes facts easier to remember. Second, moving the unknown and the equal sign builds a true understanding of what an equation means. Third, matching cards turns practice into a game, so children solve many problems while staying engaged.
Ideas for Teachers and Parents
Print the cards on cardstock and keep them in a zip-top bag for a reusable center. Let students check answers with counters or by counting on with their fingers. At home, use this monkey business adding with an unknown number activity as a quick game before dinner, or have your child make up a new equation card for you to solve.
Related Resources
What teachers say
Reviews
Write a review, earn store credit
Get 25¢ in credit for every approved review of a resource you’ve downloaded, played or purchased — up to 15 a month. Credit applies automatically to your membership payments, so your reviews can help pay for your membership.
Honest reviews only — any star rating earns the same. Program rules
Log in to write a review and earn store credit.
This adding and subtracting within 20 worksheet gives first graders mixed addition and subtraction fact practice with a helpful number line. Includes a complete answer key for quick, no-prep math review.
This adding and subtracting to 20 worksheet gives 1st graders ten mixed addition and subtraction equations to solve within 20. Answer key included — perfect for quick, no-prep math fact practice at home or school.
This Adding Word Problems with 3 Numbers Worksheet helps 1st graders add three single-digit numbers using fun story problems about ducks, apples, and more. Includes a complete answer key for quick, no-prep addition practice.
This Adding 3 Whole Numbers Within 20 Worksheet gives 1st graders twelve problems to practice adding three single-digit numbers for sums up to 20. Includes a complete answer key for fast, no-prep addition practice.
This Ten More Ten Less Worksheet gives 1st graders eight quick problems to find ten more and ten less than a two-digit number. Includes an answer key for fast, no-prep place value practice.
A first-grade commutative and associative properties worksheet where students solve ten addition problems by adding the numbers in any order or group. Includes an answer key and a handy reminder box for no-prep math practice.
This counting on to add worksheet helps 1st graders start from the bigger number and count forward on a number line to twenty. An answer key is included, so checking work takes seconds.
This adding tens and ones worksheet helps 1st graders build two-digit numbers with base ten blocks and column addition. Includes an answer key for quick, no-prep place value practice at home or school.
This Adding In Any Order Worksheet helps 1st graders see that 3 + 4 and 4 + 3 always match, using picture groups first and quick fact flips second. Answer key included, so practice takes minutes to check.
This Word Problems Adding 3 Numbers Worksheet gives 1st graders five short stories to solve by writing and adding a three-number equation. Answer key included, so practice with sums to 20 stays quick and stress-free.
This finding the missing number worksheet gives first graders focused practice solving for the unknown number in addition and subtraction equations within 20. Includes an answer key — a quick, no-prep way to build number sense and fact fluency.
This writing addition sentences worksheet gives 1st graders six picture-friendly word problems to solve by filling in each addition number sentence. Answer key included — perfect for no-prep addition practice at home or in class.
Reviews
There are no reviews yet