Grades 9-10 Video Solutions 2026-2026_9-10

Video Transcription

Video Summary

Christina must place the numbers 1–7 so adjacent boxes always add to an odd number, meaning the numbers must alternate parity. Since 2 and 5 are already fixed, the pattern is determined by alternating even and odd numbers. Then, to avoid any three consecutive boxes summing to a multiple of 3, the number 3 cannot go in either of the first two odd positions, so it must go in the remaining odd position. Similarly, the last three boxes force the 6 and 4 into the remaining even spots. The shaded boxes contain 4 and 3, so their sum is <strong>7</strong>.

Keywords

parity

adjacent boxes

odd sum

number placement

multiple of 3