Max Conquers the April Fools' Trick House

About this Grade 1 Adding Multiples Of 10 Drill

Adding multiples of 10 is a foundational skill that helps six- and seven-year-olds recognize patterns in our number system and builds mental math confidence. When children understand that 20 + 30 = 50, they're learning that tens can be counted just like ones—a critical insight for place value understanding. This skill makes later addition and subtraction much easier because students realize they can work with groups of 10 instead of counting every single object. In daily life, children see multiples of 10 everywhere: counting coins, pages in books, and days on a calendar. Mastering this concept now prevents frustration later and shows kids that math has logical, repeatable patterns. Even an April Fools' joke about mysterious missing tens becomes silly and obvious once students truly grasp how tens work together.

What your student will practice

• Fluently add two multiples of 10 within 100 using tens place understanding
• Recognize and apply the pattern that 3 tens plus 2 tens equals 5 tens
• Solve word problems involving sums of multiples of 10
• Explain adding multiples of 10 using tens blocks or drawings

Common mistakes to watch for

The most common error is when students revert to counting by ones instead of recognizing tens as units. For example, a child might count 1, 2, 3... up to 20, then continue counting 1, 2, 3... up to 30, arriving at an incorrect sum because they lose track. Another frequent mistake is writing the answer as a two-digit number incorrectly—answering "3" instead of "30" when solving 10 + 20. Watch for students who can say "2 tens plus 3 tens is 5 tens" but then write "25" instead of "50." These students understand the concept but haven't yet connected the verbal pattern to the written numeral.