Monster Mash Addition Worksheet | Grade 2 Printable

This Grade 2 addition worksheet strengthens fluency with two-digit and three-digit addition through 18 carefully sequenced problems, all wrapped in a playful monster theme that keeps young learners motivated. Students practice regrouping across place values while building the computational confidence required by second-grade math standards.

At a Glance

• Grade: 2 · Subject: Math
• Standard: CCSS.MATH.CONTENT.2.NBT.B.5 — Fluently add and subtract within 100 using place-value strategies
• Skill Focus: Addition with regrouping
• Format: 1 page · 18 problems · Answer key included · PDF
• Best For: Independent practice or math centers
• Time: 10–20 minutes

What's Inside

The worksheet presents 18 vertical addition problems arranged in a clean grid layout. Problems range from two-digit plus two-digit sums to three-digit plus two-digit sums, requiring students to regroup across the ones and tens places. Each problem sits inside its own bordered cell, giving students ample workspace. A full answer key is provided on a separate page, making self-checking or teacher grading quick and straightforward. Friendly monster illustrations border the page, reinforcing the engaging "Monster Mash Mix" theme without distracting from the math content.

Skill Progression

• Guided practice: The first column of problems features two-digit addends with simpler regrouping in the ones place, allowing students to warm up with familiar number combinations.
• Supported practice: Middle problems introduce larger addends and regrouping across both the ones and tens columns, increasing cognitive demand while the consistent vertical format provides structural support.
• Independent practice: The final problems include three-digit sums and multi-step regrouping, pushing students toward full fluency without scaffolds. This gradual-release structure mirrors the I Do, We Do, You Do instructional model.

Standards Alignment

This worksheet targets CCSS.MATH.CONTENT.2.NBT.B.5: "Fluently add and subtract within 100 using strategies based on place value, properties of operations, and/or the relationship between addition and subtraction." Several problems extend into three-digit sums, providing a natural bridge to CCSS.MATH.CONTENT.2.NBT.B.7, which asks students to add and subtract within 1,000 using concrete models, drawings, and strategies based on place value. Both standard codes can be copied directly into lesson plans, IEP goals, or district curriculum mapping tools.

How to Use It

Assign this worksheet after direct instruction on regrouping to reinforce the algorithm during guided or independent practice. It also works well as a morning warm-up or math-center rotation activity. For a formative-assessment check, observe whether students consistently line up digits by place value and whether they record the regrouped ten above the tens column — errors in either step signal the need for reteaching with base-ten blocks. Most students complete all 18 problems in 10 to 20 minutes.

Who It's For

Designed for second graders working at or approaching grade level in multi-digit addition. Students who need extra support benefit from pairing this sheet with a base-ten block manipulative mat, while advanced learners can be challenged to estimate each sum before computing. This worksheet pairs naturally with a place-value anchor chart displayed during practice.

The Monster Mash Mix worksheet aligns to CCSS.MATH.CONTENT.2.NBT.B.5, targeting fluent addition within 100 and extending into three-digit sums that preview third-grade expectations. The skill — adding multi-digit numbers using place-value strategies and regrouping — is identified by NAEP data as a foundational competency where second graders frequently show uneven mastery, particularly when regrouping across two place-value columns simultaneously. Research by Fisher & Frey (2014) confirms that structured, graduated problem sets with immediate answer-key feedback accelerate procedural fluency while reducing math anxiety. With 18 problems, a clear vertical format, and a motivating monster theme, this resource gives teachers a reliable, print-ready tool for both practice and informal assessment of addition regrouping skills in the primary grades.