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This Adding Multiples Of 10 drill has 40 problems for Grade 1. Gardening theme. Answer key included.
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Max discovered hungry birds eating all the seeds! He must collect 10, 20, 30 seeds before they escape.
Standard: CCSS.MATH.1.NBT.C.4
Preview
Page 1 — Drill
Page 2 — Answer Key
What's Included
About this Grade 1 Adding Multiples Of 10 Drill
Adding multiples of 10 is a cornerstone skill that helps first graders understand our base-10 number system and build mental math fluency. When children grasp that 20 + 30 = 50, they're recognizing patterns in how numbers work—not just memorizing facts. This skill directly supports place value understanding, which is essential for all future computation. Six- and seven-year-olds who master this develop confidence with larger numbers and begin to see math as logical rather than random. The ability to add tens prepares them for two-digit addition and subtraction without regrouping, a major milestone in Grade 1. Beyond the worksheet, this skill shows up everywhere: counting flower seeds in groups of 10, organizing toy collections, or saving allowance. Building this foundation now prevents gaps that often slow progress in multiplication and division later.
What your student will practice
- Fluently add two multiples of 10 within 100 using tens understanding
- Recognize and extend patterns when adding tens (10 + 20, 20 + 30)
- Apply mental strategies to solve multiples-of-10 addition without counting by ones
- Translate real-world quantities grouped by tens into addition equations
Common mistakes to watch for
The most frequent error is children reverting to counting by ones instead of counting by tens. For example, when solving 30 + 40, a child might count "31, 32, 33..." rather than "3 tens + 4 tens = 7 tens." Another common pattern is forgetting the zero: writing 7 instead of 70 as the answer. You'll spot this mistake when the child answers "7" to "20 + 50." Some students also confuse the digit in the tens place with the total, saying "5" for the answer to "20 + 30" because they're only adding the non-zero digits (2 + 3) and ignoring that these represent tens. Watch for children who write correct intermediate thinking but write the wrong final number.
Play a "tens groups" game at home using small objects like coins, buttons, or snack crackers. Have your child make two piles of 10 items each, then count the total piles: "I have 2 tens and 3 tens—that's 5 tens, or 50!" Do this 4–5 times with different combinations (2 tens + 4 tens, 1 ten + 6 tens), saying the sentence aloud each time. The physical grouping and verbal rehearsal lock in the tens pattern without worksheet fatigue. You'll see the shift when your child stops needing the objects and can picture the tens in their head.