1st Grade · Math · Parent guide

Use Addition Properties to Add and Subtract1.OA.B.3

Short answer. 1.OA.B.3 covers the ideas behind 8 + 3 = 3 + 8 and grouping numbers to make ten. Plain-language help for parents, plus quick kitchen-table practice.

Grade: 1st Grade
Subject: Math
Framework: Common Core

Quick answer

What 1.OA.B.3 means in plain English

Behind the official wording sit two friendly ideas. First: order doesn't change a sum, so if your child knows 8 + 3 = 11, she also knows 3 + 8 = 11 for free (teachers call this the commutative property). Second: when adding several numbers, you can group them any way you like, so 2 + 6 + 4 becomes 2 + 10 = 12 (the associative property). First graders don't need the vocabulary; they need to use the moves.

Why parents see this skill

Why this matters

These two properties cut the number of facts a child has to memorize roughly in half and turn clunky problems into quick ones. They're also the quiet foundation for the mental math and algebra rules she'll lean on for years, where rearranging is half the game.

For reference

The official wording

CCSS.MATH.CONTENT.1.OA.B.3

Apply properties of operations as strategies to add and subtract. Examples: If 8 + 3 = 11 is known, then 3 + 8 = 11 is also known. (Commutative property of addition.) To add 2 + 6 + 4, the second two numbers can be added to make a ten, so 2 + 6 + 4 = 2 + 10 = 12. (Associative property of addition.)

Official Common Core source

See it, then try it

How this skill can look at home

You do not need a lesson plan. Look for these signs in ordinary play, reading, and conversation, then choose one short activity.

What you may notice

Your child flips a hard problem around on her own, turning 2 + 9 into 9 + 2 so there's less to count.
She spots pairs that make 10 inside a longer problem, like grabbing the 6 and 4 in 6 + 3 + 4.
She can tell you that 5 + 7 and 7 + 5 will match without recounting.
She uses a known addition fact to answer a related subtraction question.

Simple ways to practice

01
Flip the Towers
Build two block towers, one of 3 and one of 9. Count the total, then swap the towers' positions and ask if the total changed. Kids laugh at how obvious it feels, and that's the point. Repeat with new pairs until she predicts 'same!' before you swap.
02
Make-Ten Hunt
Write three numbers on scraps of paper, like 7, 5, 3, and ask her to find the two that make 10 before adding the leftover. Do three or four rounds with different trios. Say the finished move out loud together: '7 and 3 is 10, and 5 more is 15.'
03
Card Flip Pairs
Deal two playing cards (ace through 9) face up and add them. Then flip their positions and ask for the sum again. When she answers instantly without recounting, she's using the property. Let her be the dealer next round and quiz you.

Choose what helps today

Start with the domain guide for context, use the learning library when a concept needs explaining, or print a page when your child is ready to practice.

Frequently asked questions

Does my first grader need to know the words 'commutative' and 'associative'?

No. The standard asks kids to use these properties as strategies, not recite definitions. If your child flips 3 + 8 into 8 + 3 because it's easier to count on from 8, she's meeting the standard. The formal names show up years later.

How do schools even test something this abstract?

Usually with concrete questions: 'If 8 + 3 = 11, what is 3 + 8?' or 'Show an easy way to add 2 + 6 + 4.' Teachers also watch how kids solve problems during class. There's rarely a separate quiz on it; it's woven into everyday addition work.

Keep the sequence

More standards in 1.OA

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