standard_description: Find the greatest common factor of two whole numbers less than or equal to 100 and the least common multiple of two whole numbers less than or equal to 12. Use the distributive property to express a sum of two whole numbers 1–100 with a common factor as a multiple of a sum of two whole numbers with no common factor. For example, express 36 + 8 as 4 (9 + 2).
problem_activity: Task
The table below shows all the products of pairs of numbers between 1 and 9.
[IMG]
Which numbers appear only once in the table of products?   Where are these numbers located in the table?  Why?
Which numbers appear the most frequently in the table?  Why?
Which numbers between 10 and 20 do  not  appear in the table?  What do these numbers have in common?


aligns: no