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About this Grade 1 Adding Multiples Of 10 Drill

Adding multiples of 10 is a foundational bridge between counting and true addition for first graders. When children master this skill, they're learning that 20 + 30 really means "2 tens plus 3 tens equals 5 tens," which builds number sense far beyond memorized facts. This skill directly supports mental math strategies that will carry through elementary school and makes real-world situations—like combining dimes or organizing objects into groups of 10—suddenly make sense. At ages 6–7, students' brains are developing the ability to recognize patterns and break numbers into meaningful chunks. By practicing adding multiples of 10, children strengthen their understanding of place value, the foundation of our entire number system. They also gain confidence working with larger numbers without relying solely on counting on fingers, moving them toward true mathematical thinking.

What your student will practice

• Recognize that multiples of 10 follow a pattern (10, 20, 30, 40, 50)
• Add two multiples of 10 using tens knowledge rather than counting by ones
• Solve single-digit addition with multiples of 10 (e.g., 3 + 20, 40 + 5)
• Apply adding-multiples-of-10 to real-world grouping scenarios

Common mistakes to watch for

Many first graders treat 20 + 30 the same way they'd solve 2 + 3, arriving at 5 instead of 50—they ignore the zeros entirely. Others will attempt to count by ones from the start rather than using the tens pattern, which exhausts their working memory and leads to errors. You'll spot this when a child counts "21, 22, 23..." instead of recognizing "2 tens plus 3 tens = 5 tens." Another common pattern: students correctly add the tens digits (2 + 3 = 5) but then forget to write the zero, writing "5" instead of "50."