Garret has $1.74. Pencils cost $0.15 each, and he bought 10 pencils. How much money does Garrett have left?

To find out how much money Garret has left after buying 10 pencils, we first need to calculate the total cost of the pencils.

The cost of one pencil is $0.15. Therefore, the cost for 10 pencils can be calculated as follows:

\[
\text{Total cost} = \text{Cost per pencil} \times \text{Number of pencils} = 0.15 \times 10 = 1.50
\]

Now, we will subtract the total cost of the pencils from the amount of money Garret initially had:

\[
\text{Money left} = \text{Initial amount} - \text{Total cost} = 1.74 - 1.50
\]

Calculating that gives:

\[
\text{Money left} = 1.74 - 1.50 = 0.24
\]

Thus, Garret has \( \boxed{0.24} \) dollars left.