10/26/26 - Teachers and Parents - subscribe today to access everything on the site. We offer AFFORDABLE forever, annual, and monthly subscriptions. Join tens of thousands of teachers who are already on board.

Advertisement

Remove ad

This activity requires students to find the "intruder" amongst four associated numbers. For example in the set 7, 15, 4, 8, "4" would be the intruder number because 7, 15, and 8 can be used to form facts together. 4 cannot be combined with two other numbers in the set to produce any facts.

Related activities

Advertisement

Remove ad