Final answer:
The best choice for the first number to be subtracted from 2,378 using partial quotients when dividing by 22 is 2,200, because it is a multiple of 22 that easily subtracts from 2,378. Therefore, the correct answer is option d. 2,200.
Step-by-step explanation:
When using partial quotients to solve 2,378 divided by 22, the goal is to find a number that 22 can multiply into comfortably and falls under 2,378.
The best choice for the first number to be subtracted from 2,378 is 2,200 (d). This is because you can easily determine how many times 22 goes into 2,200 by identifying that 22 times 100 equals 2,200.
Subsequently, you subtract 2,200 from 2,378, leaving a smaller number to work with as you continue the division process using partial quotients.