Max Rescues the Robot Factory: Adding Tens Challenge

About this Grade 1 Adding Multiples Of 10 Drill

Adding multiples of 10 is a cornerstone skill that helps first graders understand how our base-10 number system works. When children master 10 + 20 or 30 + 40, they're learning to think in chunks rather than counting by ones—a huge leap in mathematical thinking. This fluency builds confidence with larger numbers and makes future addition and subtraction feel manageable instead of overwhelming. By recognizing that 10, 20, 30, and beyond follow predictable patterns, six- and seven-year-olds develop number sense that will support multiplication, place value, and mental math for years to come. Most importantly, this skill reflects real life: counting coins, organizing objects into groups of 10, and thinking about money or classroom supplies naturally involve multiples of 10. The repetition in these drills rewires how children's brains organize numbers, moving them from concrete counting to abstract thinking.

What your student will practice

• Fluently add two multiples of 10 within 100 using mental strategies
• Recognize the ones place stays zero when adding multiples of 10
• Apply place-value understanding to solve addition problems with tens
• Build automaticity so answers come without counting by ones

Common mistakes to watch for

The most common error is watching students revert to counting by ones instead of recognizing the pattern in tens. For example, a child might count 1, 2, 3... to solve 20 + 30 rather than thinking "2 tens plus 3 tens equals 5 tens." Another frequent mistake is forgetting the zero in the ones place and writing 5 instead of 50. Teachers and parents can spot this by asking the child to explain how they found the answer—if they're pointing at fingers or saying individual numbers, they're counting by ones. If the answer lacks a zero in the ones place, they've lost track of what digit represents.