Mr. R.’s World of Math

Ok, as a reminder, Mr. R. was going to choose 2 students to go back into the crumbling classroom. Any student that has a problem with an answer equal to 5,678 will be the first student to return to the dangerous classroom to try to save Cocoa.

Here are the names with the problems:

JUSTIN         5,670 + 7
JUSTIN         4,004 – 38
SERENA       5,454 + 223
DAVID           6,005 – 5,009
GREG           5,300 + 345
SERENA       4,567 + 2,333
GREG           5,677 + 1

Which two students have problems that have an answer that equals 5,678?