Max Collects Fall Leaves: Add by Tens Race!

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 toward mental math fluency. When children recognize that 20 + 30 is really just "2 tens plus 3 tens equals 5 tens," they begin to understand place value deeply—not just memorize facts. This skill makes larger addition problems feel manageable and boosts confidence when kids encounter word problems about collecting items or combining groups. At age 6 and 7, brains are developing the ability to spot patterns and think about numbers in groups rather than individual units. Mastering multiples of 10 also prepares students for two-digit addition and subtraction, which appear in most Grade 1 curricula. As fall arrives and children might count pumpkins or apples in groups of 10, this real-world connection reinforces why adding by tens matters.

What your student will practice

• Recognize multiples of 10 as groups of tens
• Add two multiples of 10 without counting on fingers
• Apply tens-addition to simple word problems
• Explain addition of multiples of 10 using place value language

Common mistakes to watch for

The most common error is that students add the tens digits correctly but then write the answer without the zero—for example, writing "5" instead of "50" for 20 + 30. Another frequent mistake is reverting to counting by ones instead of recognizing the pattern, so a child counts "21, 22, 23..." from 20 when adding 20 + 10. You can spot these mistakes by watching whether the child pauses to count on fingers or whether they confidently answer without using fingers but forget the final zero. Listen carefully when they explain their thinking; if they say "2 + 3 is 5," they may not be connecting tens to their answer.