Adding whole tens, missing number

Before handing out the worksheet, briefly introduce the concept with a short oral warm-up or a visual model on the board. Encourage students to talk through their thinking as they work: "What strategy are you using? How do you know that is right?" After completing the worksheet, review any missed problems together and discuss the reasoning rather than just the answer. For extra support, let students use manipulatives or draw pictures alongside the written problems. These adding whole tens, missing number worksheets work well as daily practice, homework, or a focused review activity.

These adding whole tens, missing number worksheets for 2nd grade give students the structured, hands-on practice they need to build confidence and fluency. Students work through a range of problem formats, from visual models and diagrams to written equations and word problems, so they encounter adding whole tens, missing number from every angle. Each worksheet is designed to build on prior knowledge while introducing the level of challenge appropriate for 2nd grade. Practicing adding whole tens, missing number at this stage strengthens the mathematical foundations that support more advanced concepts in later grades.

"Adding whole tens, missing number" is written for 2nd Grade (Ages 7-8), and it covers Common Core 2.OA.B.2. If your little one is a year younger but already steady on addition, the page still works. You may just need to read the instructions out loud. And if they are older and adding whole tens, missing number never quite stuck, this is a short review rather than busywork.

Yes, both. We made it for 2nd Grade addition, and the page works the same whether it lands on a kitchen table or a center rotation. At home, most families go through it together and talk the answers out loud, and that talking is where most of the learning happens with adding whole tens, missing number. In class it runs well as independent work while you pull a small group. Print one copy or thirty, whichever the day needs.

Standard problems ask for the sum; missing-number problems ask students to identify which multiple of 10, when added, produces the given total - requiring subtraction thinking.

Students who know their single-digit addition and subtraction facts can translate them directly to the tens (e.g., 9 - 4 = 5 means 90 - 40 = 50 means 40 + ___ = 90 → 50).

Extend the number range to within 1,000 or include three-addend missing-number problems (e.g., 20 + ___ + 40 = 100) to provide additional challenge.

Second graders should fluently add within 20 (CCSS 2.OA.B.2) and add within 100 using strategies based on place value and properties of operations (2.NBT.B.5). They also begin adding within 1,000 using models and drawings (2.NBT.B.7).

Regrouping (carrying) is typically introduced mid-year in second grade when students add two-digit numbers that sum to more than 9 in the ones place. Understanding place value is a prerequisite. Use base-ten block worksheets before transitioning to the standard algorithm.

By the end of second grade, students should know all addition facts within 20 from memory (CCSS 2.OA.B.2). That is 100 facts (0+0 through 9+9, plus the commutative pairs). Daily timed practice with addition fact worksheets helps build automaticity.