Q: A park had 200 visitors last Saturday and 40 more visitors on Sunday than on Saturday. Calculate the total number of people in the park over the two days.
A: If on Sunday 40 more people were present at the park than on Saturday, there were 200 + 40 = 240 people on Sunday. The total number of people at the park over the two days is 240 + 200 = 440. The answer is 440.

Q: A notebook costs three times as much as a pen. If a pen costs $1.50, how much will Lyle pay for 4 notebooks?
A: A notebook costs $1.50 x 3 = $4.50. So Lyle will pay $4.50 x 4 = $18 for the 4 notebooks. The answer is 18.

Q: Xavier needs 84 paper plates for a housewarming party. He already has 21 green plates and 28 red plates. How many more plates should Xavier buy?
A:
The total number of green and red plates is 28 + 21 = 49. Xavier should buy 84 − 49 = 35 more plates. The answer is 35.