Wyoming Math 1.NBT.4

1.NBT.4 is a cluster heading. These are the individual standards under it.

• 1.NBT.4a

  Including adding a two-digit number and a one-digit number.

• 1.NBT.4b

  Adding a two-digit number and a multiple of 10.

• 1.NBT.4c

  Understand that in adding two-digit numbers, adds tens and tens, ones and ones; and sometimes it is necessary to compose a ten.

• 1.NBT.4d

  Relate the strategy to a written method and explain the reasoning used.

01

What Students Need to Do

Students add within 100 using blocks or drawings, including adding one-digit and two-digit numbers to two-digit numbers. They combine tens with tens and ones with ones, making a new ten when needed. They show how their model matches a written method and explain their steps.

02

What Mastery Looks Like

For 27 + 15, a student shows 3 tens and 12 ones, trades 10 ones for a ten, and writes 42. For 36 + 20, they keep the 6 ones and get 56.

03

Common Misconceptions

Some students write 27 + 15 = 312 because they leave 12 ones instead of making a ten. Others change the ones digit when adding 20 or count a traded ten twice.

04

How to Assess It

Exit ticket: Draw tens and ones to solve 28 + 15, then write the matching equation. Show where you trade 10 ones for a ten.

1. 01

   Give pairs base-ten rods and cubes to build 28 + 15, trade 10 cubes for a rod, and record the sum.

2. 02

   Ask students to draw 34 + 20 and write why the tens change but the ones stay the same.

3. 03

   Play a card game: draw two numbers from 10 to 49, sketch tens and ones, add, and check a partner's work.

4. 04

   Tell students a library has 28 books and receives 15 more, then have them sketch and total the books.

• 2.NBT.7

  Add and subtract within 1,000, using concrete models or drawings and strategies based on place value, properties of addition, and/or the relationship between ad...

• 3.NBT.2

  Fluently add and subtract within 1,000 using strategies and algorithms based on place value, properties of addition, and/or the relationship between addition an...

• 2.NBT.5

  Add and subtract within 100 using strategies based on place value, properties of addition, and/or the relationship between addition and subtraction.