Max Discovers Ancient Artifacts: Add by Tens!

About this Grade 1 Adding Multiples Of 10 Drill

Adding multiples of 10 is a foundational skill that helps first graders see patterns in our number system and builds confidence with larger numbers. When children understand that 20 + 30 = 50, they're not just memorizing facts—they're learning that tens work just like ones, which is crucial for place value understanding. This skill makes mental math faster and easier, so kids can solve problems without counting on their fingers every time. It also prepares them for two-digit addition and subtraction later in the year. At ages 6 and 7, children's brains are developing the ability to recognize and apply patterns, and multiples of 10 are the clearest patterns in our number system. Real-world situations like combining groups of coins or counting by tens in a collection (much like an archaeologist organizing artifacts into sets) give this abstract concept concrete meaning.

What your student will practice

• Recognize and name multiples of 10 up to 100
• Add two multiples of 10 using mental strategies
• Explain addition of multiples of 10 using tens and ones language
• Apply adding multiples of 10 to solve simple word problems

Common mistakes to watch for

Many first graders add the tens place correctly but then forget to write zero in the ones place, writing 5 instead of 50 for 20 + 30. Others may count by ones instead of recognizing the pattern, turning a quick mental task into slow, error-prone counting. Watch for students who line up numbers incorrectly on paper or who treat 30 + 40 the same way they'd treat 3 + 4, not yet seeing that the zeros matter. The quickest way to spot confusion is to ask them to show their thinking aloud—if they're counting on fingers or hesitating on every problem, they haven't yet grasped that this is really just adding the tens digits.