Final answer:
By multiplying the number of playground balls per shipment (60) by the number of shipments (90), we find that there will be a total of 5400 playground balls.
Step-by-step explanation:
To calculate the total number of playground balls in 90 shipments when each shipment contains 60 balls, we use multiplication. We multiply the number of balls per shipment by the number of shipments:
60 balls/shipment × 90 shipments = 5400 balls.
Therefore, there will be 5400 playground balls in 90 shipments.