# Adding 3 Numbers Worksheet (Within 20)

Looking for high-quality Math worksheets aligned to Common Core standards for Grades K-8?

Our premium worksheet bundles contain 10 activities and answer key to challenge your students and help them understand each and every topic within their grade level.

------ Note: The Information above this point will not be sent to your printer --------

1. Think of the easiest order for you* in which to add the three numbers in each box.
2. Write the number sentence to show the order and the sum. The first one is done for you.

* Your order might be different from the answers. This is OK as it is the order that is easiest for you that matters.

You will find a similar worksheet here where two of the three numbers always add up to 10. Trying to find two numbers that add to 10 is very good way when adding up three or more numbers.

 5 4 3   5+4+3 = 12 8 2 4   8+2+4 = 14 6 1 11   11+1+6 = 18 4 9 5   4+5+9 = 18 5 7 8   8+5+7 = 20 6 7 4   6+4+7 = 17 7 3 6   7+3+6 = 16 5 2 4   5+4+2 = 11 2 7 9   9+2+7 = 18

------ Note: The Information below this point will not be sent to your printer --------

## Related Resources

The various resources listed below are aligned to the same standard, (1OA06) taken from the CCSM (Common Core Standards For Mathematics) as the Addition and subtraction Worksheet shown above.

Add and subtract within 20, demonstrating fluency for addition and subtraction within 10. Use strategies such as counting on; making ten (e.g., 8 + 6 = 8 + 2 + 4 = 10 + 4 = 14); decomposing a number leading to a ten (e.g., 13 - 4 = 13 - 3 - 1 = 10 - 1 = 9); using the relationship between addition and subtraction (e.g., knowing that 8 + 4 = 12, one knows 12 - 8 = 4); and creating equivalent but easier or known sums (e.g., adding 6 + 7 by creating the known equivalent 6 + 6 + 1 = 12 + 1 = 13).