Max Conquers the Smoothie Shop: Adding by Tens!

About this Grade 1 Adding Multiples Of 10 Drill

Adding multiples of 10 is a cornerstone skill that helps first graders recognize patterns in our number system and build mental math fluency. When children master 20 + 30 or 40 + 10, they're developing number sense that will support all future arithmetic. This skill also teaches them that tens can be bundled and moved around—a key insight for place value understanding. At age 6-7, brains are primed to spot patterns, and multiples of 10 are the clearest, most repeatable pattern in early math. Real-world situations, like counting coins at a smoothie shop or tracking price totals, show kids exactly why these combinations matter. Building confidence with tens also reduces anxiety around math and helps students feel capable when they encounter larger numbers.

What your student will practice

• Add two multiples of 10 (10, 20, 30, etc.) accurately and fluently
• Recognize that tens place digits add independently from ones place
• Apply adding-multiples-of-10 to solve simple word problems
• Explain adding-multiples-of-10 strategies using tens language

Common mistakes to watch for

First graders often forget to focus only on the tens digits and try to add the whole numbers as if they were single units, arriving at incorrect sums like 2 + 3 = 5 instead of 20 + 30 = 50. Another common slip is writing the answer correctly but misplacing the zero—they might say 50 but write 5. Some students also confuse the process and add one number correctly but forget the second addend entirely. Watch for hesitation or finger-counting on every problem; this signals the student hasn't yet internalized the pattern that 10 + 10 always equals 20.