Which of the following pairs of numbers add to $10$10?
$3$3 and $7$7
$2$2 and $8$8
$5$5 and $5$5
$1$1 and $9$9
How many more do we need to add to $1$1 to get to $10$10?
How many more do we need to add to $9$9 to get to $10$10?
We want to find $6+5$6+5.