Why when it asks you for acutal interest does it divide the construction loan by 10/12, but the 3 year and 10 year loan it just uses the interest rate and nothing else??

Joyful Toys hired a contractor to build new equipment for its manufacturing plant. The total expected cost is $700,000. The project began on March 1, 2021 and should be completed sometime in 2022 Joyful Toys has the following debt outstanding: Construction loan signed March 1, 2021 for $250,000; interest rate = 6% 3-year loan signed in 2020 for $400,000; interest rate = 5% 10-year loan signed in 2018 for $100,000; interest rate = 7% Joyful Toys made the following progress payments to the contractor in 2021 May 1 $100,000 August 1 $180,000 November 1 $200,000 December 31 $ 50,000 Total $530,000 Instructions: a Compute actual interest for 2021 Construction loan: 250,000 x .06 x 10/12 = 3 year loan: 400,000 x .05 = 10 year loan: 100,000 x .07 = Total Actual Interest 2021 12,500 20,000 7,000 $39.500