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You can make a calculator count for you by pressing the keys
$1 + = = $
$1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12$
To make it count by twos, press $2 + = = $
$2, 4, 6, 8, 10, 12$
You can make it count by any number you choose.
Now the question:
You can count by ones to reach $24$.
You can count by twos to reach $24$.
What else can you count by to reach $24$?