CHALLENGE 3: BUBBLE MATHS

WHY IT MAY WORK: In a 2019 University of Exeter study of people aged 60 to 93, researchers found that those who did number puzzles at least once a day scored higher for working memory, verbal reasoning and learning than those who tried them once a month or less.

PLAY IT: Assign exactly one whole number from one to seven to each of the seven bubbles. Each number occurs only once. The sums of some of the numbers are revealed in the areas where their bubbles overlap.