Max Conquers the Geyser Valley: Adding Tens Race!

About this Grade 1 Adding Multiples Of 10 Drill

Adding multiples of 10 is a foundational skill that helps first graders recognize patterns in our number system and builds mental math fluency they'll use for the rest of their math journey. When children grasp that 20 + 30 = 50, they're learning that tens work just like ones—a crucial insight for place value understanding. This skill also makes real-world math faster and more confident: counting coins, organizing classroom supplies into groups of 10, or tracking points in a game all rely on this ability. At ages 6–7, students' brains are primed to notice and repeat patterns, making this the ideal time to cement tens-based thinking. Mastering adding multiples of 10 removes a major cognitive bottleneck that can slow down two-digit addition, subtraction, and later multiplication. When children feel confident adding tens, they approach larger math problems with less anxiety and more independence.

What your student will practice

• Recognize that multiples of 10 follow a predictable pattern and can be added like single digits
• Add two multiples of 10 mentally without counting on fingers or drawing pictures
• Explain why 30 + 40 equals 70 using tens language (three tens plus four tens)
• Apply adding multiples of 10 to simple story problems involving groups or collections

Common mistakes to watch for

Many first graders try to add the zeros separately, incorrectly writing 20 + 30 = 50 as "2 + 3 = 5, then add two zeros to get 500." Another common pattern is counting by ones instead of recognizing the tens: a child might count "20, 21, 22..." instead of "20, 30, 40." Watch for students who lose track of which digit represents tens when problems mix single digits and multiples of 10. You'll spot this error if they write 5 + 20 = 25 but struggle to explain which represents the tens place.