Sums across 10 (eg. 6 + 8)
Addition across 10 (eg. 39 + 5)

Here are some strategies for adding two numbers resulting in a sum exceeding 10 using mental math:

1. Make a Ten:
This strategy works best when one number is close to 10, and the other has some ones that can be “borrowed” to create a ten with the first number.
Example: 18 + 5 becomes 18 + 2 + 3 = 20 + 3 = 13.
2. Counting On:
Start with the larger number and count on the smaller number. This is particularly useful when dealing with small increments. Example: 27 + 2 becomes 28, 29.
If both numbers are close to a double, add the double of the larger number and adjust by adding or subtracting the difference between the smaller number and its double.
Example: 18 + 17 can be done as 18 + 18 - 1 = 36 - 1 = 35.

Tips:
Practice regularly to improve your speed and accuracy.
Choose the strategy that works best for you and the specific problem.

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### More Addition Across 10 Worksheets

Missing Addend (sums < 10) (eg. __ + 5 = 7)
Missing Addend Word Problems (eg. 8 + __ = 17)

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