$k$k represents the number of basketballs used during a training session.
The picture below shows the basketballs that were used for training last Saturday. What is the value of $k$k in this case?
$x$x represents the number of cupcakes baked for a party.
The picture below shows the number of cupcakes made for Oprah's party. What is the value of $x$x in this case?
Let $p$p represent "the number of tennis balls in a pack".
Let $x$x represent "a number of squares".