Skip to main content
Common Core Math1st GradeNumbers in Base Ten

1.NBT.6: Subtract Multiples of 10

Also written as 1.NBT.C.6 and CCSS.MATH.CONTENT.1.NBT.C.6 · Cluster: Use place value understanding and properties of operations to add and subtract.

Make a Subtraction WorksheetAll 21 1st Grade Math Standards

The Official Wording

Subtract multiples of 10 in the range 10-90 from multiples of 10 in the range 10-90 (positive or zero differences), using concrete models or drawings and strategies based on place value, properties of operations, and/or the relationship between addition and subtraction; relate the strategy to a written method and explain the reasoning used.

Common Core State Standards, Grade 1, Number & Operations in Base Ten · Read it at the source · Checked October 14, 2026

What 1.NBT.6 Means in Plain English

First graders subtract one multiple of ten from another, both between 10 and 90, like 80 - 50. With ten-rods it is 8 tens take away 5 tens, which leaves 3 tens, or 30. The answer can be zero, as in 40 - 40.

Each model gets linked to a written method and explained, so a student might count up 60, 70, 80 from 50, or use 5 + 3 = 8 to know 50 + 30 = 80. In 2nd grade subtraction covers any two-digit numbers within 100 (2.NBT.5).

1.NBT.6 I Can Statements

  • I can subtract tens from tens using rods or drawings.
  • I can use 8 - 5 = 3 to solve 80 - 50.
  • I can explain how I subtracted using tens.

1.NBT.6 Worked Example

A straw count taken away ten at a time, then explained two ways.

Problem

There are 80 straws in the bin. The class uses 50 for a building project. How many straws are left?

Eight tens take away five tens
  1. This is taking away tens. Show 80 as rods of ten.8 tens
  2. Take away 5 rods for the 50 straws the class used.8 tens - 5 tens
  3. 3 rods are left. Three tens is thirty.3 tens = 30
  4. Link it to a fact you know: 8 - 5 = 3, so 8 tens - 5 tens = 3 tens.80 - 50 = 30
  5. Explain it another way: count up by tens from 50 to 80.60, 70, 80 is 3 tens
Answer30 straws are left

Check it: Add back what was used: 30 + 50 = 80, the straws in the bin at the start.

Common Mistakes with 1.NBT.6

Writing the answer as ones

80 - 50 = 3

Try this: Say the units every time, 8 tens take away 5 tens is 3 tens, and have students write 3 tens as 30.

Counting back by ones

Counts back 50 single steps from 80 and loses count

Try this: Hand out rods only, no single cubes, so the only way to take 50 is to take five tens.

Treating zero as impossible

Says 60 - 60 “can’t be done”

Try this: Build 60 with six rods, take all six away, and write what is left: 0 tens, 0 ones, the number 0.

Where 1.NBT.6 Fits

Comes Before1.NBT.2Read 10, 20 up to 90 as one to nine tens and 0 ones.1.OA.4Solve a subtraction as a missing-addend problem.
Alongside1.NBT.4Add within 100, including a two-digit number and a multiple of 10.1.NBT.5Find 10 more or 10 less in your head.
Comes Next2.NBT.5Add and subtract within 100 fluently with place-value strategies.3.NBT.3Multiply a one-digit number by a multiple of 10, like 4 × 30, with the same tens thinking.

Practice 1.NBT.6

Subtraction Worksheet GeneratorFree ToolTens minus tens like 70 - 40 and 90 - 90, with an answer key. Ask for the matching small fact, 7 - 4 = 3, beside each one.Multiples of 10Within 90Answer key
Make a Worksheet
Number Line GeneratorFree ToolA 0 to 100 line marked in tens, for counting up from the smaller number in jumps of ten: 50 to 80 is three jumps.0 to 100Step 10Labeled
Make a Number Line

Quick Check

  1. Solve 70 - 20.
  2. Solve 50 - 50.
  3. The art room had 60 sheets of paper. A class used 30. How many sheets are left?

1.NBT.6: Other Names

1.NBT.61.NBT.C.6CCSS.MATH.CONTENT.1.NBT.C.6

Common Core State Standards © Copyright 2010. National Governors Association Center for Best Practices and Council of Chief State School Officers. All rights reserved. Official wording from the Common Core State Standards PDFs at corestandards.org, last checked October 14, 2026. The explanation, I can statements, example, mistakes and practice on this page are EMStudio’s own, written beside the official wording. They are not part of the standard.