Related Pages
Make Ten Addition
Lesson Plans And Worksheets For Grade 1
More Lessons For Grade 1
Common Core For Grade 1
Videos and solutions to help Kindergarten and Grade 1 kids learn to add and subtract within 20, demonstrating fluency for addition and subtraction within 10 by using decomposing a number leading to a ten (e.g., 13 – 4 = 13 – 3 – 1 = 10 – 1 = 9).
Common Core: 1.OA.6
The following diagrams show the Make Ten Subtraction Strategy. Scroll down the page for more examples and solutions.

Printable & Online Addition Worksheets
Mental Math Strategies: Break Down To 10
How to use mental strategies to subtract within 20 using the “break down to 10” strategy?
This is one of the strategies suggested in the Common Core State Standards for Mathematics, 1.OA.6 and 2.OA.2.
With practice, this strategy can help students gain fluency when subtracting within 20. Eventually students will memorize these facts, which is expected by the end of grade 2.
Example:
14 - 9 = 14 - 4 - 5 = 10 - 5 = 5
15 - 7 = 15 - 5 - 2 = 10 - 2 = 8
17 - 8 = 17 - 7 - 1 = 10 - 1 = 9
Make 10 Subtraction Strategy
Example:
11 - 6 = 11 - 1 - 5 = 10 - 5 = 5
13 - 9 = 13 - 3 - 6 = 10 - 6 = 4
17 - 8 = 17 - 7 - 1 = 10 - 1 = 9
14 - 7 = 14 - 4 - 3 = 10 - 3 = 7
Subtraction With The Make A Ten Strategy
Example:
12 - 9 = 12 - 2 - 7 = 10 - 7 = 3
Using Ten: a Mental Math Subtraction Strategy
Using Ten is a mental math strategy that involves changing a number to ten and then adjusting the answer. Because “10” is generally an easier number to work with, this simplifies the equation making it easier to solve.
Example:
13 - 8 = 10 - 8 + 3 = 5
Check out our most popular games!
Fraction Concoction Game:
Master fractions in the lab: mix, add, and subtract beakers to create the perfect concoction!
Fact Family Game:
Complete fact families and master the link between addition & subtraction and multiplication & division.
Number Bond Garden:
Clear the board by matching number pairs that sum to ten in this garden-themed mental math puzzle.
Online Addition Subtraction Game:
Practice your addition and subtraction skills to help the penguin find its mummy.
We welcome your feedback, comments and questions about this site or page. Please submit your feedback or enquiries via our Feedback page.