Using the fact family of $5$5, $5$5, and $10$10.
$+$+ | $=$= | |||
$5$5 | $+$+ | $5$5 | $=$= | $10$10 |
What is $10-5$10−5?
Using the fact family of $7$7, $7$7, and $14$14:
We are interested in the fact family of $7$7, $7$7, and $14$14:
Using the fact family of $2$2, $5$5, and $7$7.