Mississippi Math 3.NBT.2

Math3rd GradeNumber and Operations in Base Ten2 (NBT) Use Place Value Understanding and Properties of Operations to Perform Multi-Digit Arithmetic4

The Standard

Fluently add and subtract (including subtracting across zeros) within 1000 using strategies and algorithms based on place value, properties of operations, and/or the relationship between addition and subtraction. Include problems with whole dollar amounts.

2025 Mississippi College- and Career-Readiness Standards for Mathematics · Solve problems Involving the Four Operations, and Identify and Explain Patterns in Arithmetic

Teacher's field guide

What This Standard Means

What Students Need to Do: Students add and subtract numbers within 1,000 accurately and efficiently, including subtraction across zeros. They use place value to explain their steps, check subtraction with addition, and solve problems with whole-dollar amounts.
What Mastery Looks Like: A student can solve 602 - 285 = 317, show the trades across the zero, and check by adding 317 + 285. They can also add $375 + $240 = $615 and explain their steps.
Common Misconceptions: Students may subtract the smaller digit from the larger digit in each column, no matter which number is on top. When the tens digit is zero, they may not know to trade a hundred before trading a ten.
How to Assess It: Give students 602 - 285. Ask them to show each trade and check their answer with addition.

Lesson moves

Ways to Teach It

Use base-ten blocks to build 402, trade one hundred for tens, then one ten for ones, and subtract 176.
Ask partners to sketch and explain the trades needed to solve 500 - 268.
Put pairs of three-digit numbers on cards; students subtract the smaller from the larger and check each answer by addition.
Post a $600 field trip budget and a $275 bus cost; have students find the balance and check it with addition.

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