Maryland Math 4.NOS.B.3

4.NOS.B.3 is a cluster heading. These are the individual standards under it.

• 4.NOS.B.3.a

  Apply estimation strategies to estimate sums and differences.

• 4.NOS.B.3.b

  Use computational strategies (e.g., decomposition, partials sums) efficiently.

• 4.NOS.B.3.c

  Use a standard algorithm

• 4.NOS.B.3.d

  Determine and explain when a strategy or algorithm is most efficient.

01

What Students Need to Do

Students add and subtract whole numbers within 1,000,000. They estimate answers, then calculate using place value strategies or the standard algorithm. They explain why their method fits the numbers.

02

What Mastery Looks Like

A student lines up digits by place value and regroups accurately. They can use compensation for a number near a multiple of ten or choose the standard algorithm for less friendly numbers. They check whether the answer is close to their estimate.

03

Common Misconceptions

Students may line up numbers by the last digit they wrote instead of by place value. In subtraction, they may subtract the smaller digit from the larger digit in each column, regardless of which number is on top. Some treat a rounded estimate as the exact answer.

04

How to Assess It

On an exit ticket, ask students to estimate and solve 398,750 + 204,625 and 600,000 - 298,750, then explain their method for each.

1. 01

   Give pairs place value disks to build 52,780 and 28,460, then trade disks to find the sum.

2. 02

   Ask students to compare compensation and column subtraction for 400,002 minus 199,999, then defend the faster method.

3. 03

   Play a partner relay with cards showing 345,680 + 124,210 and 780,000 - 325,450; estimate, solve, and check each round.

4. 04

   Use city library counts of 247,835 spring visits and 186,690 summer visits; estimate, then calculate total visits.

• 5.NOS.B.4

  Fluently multiply multi-digit whole numbers.

• 3.NOS.D.7

  Fluently add and subtract within 1,000.

• 6.NOS.B.2

  Fluently divide multi-digit numbers.

• 2.NOS.C.8

  Fluently add and subtract within 100.