Curated OER
Prove It!
In this problem solving skills worksheet, students prove that a number is a multiple of 9 if the sum of its digits in 9. Students also respond to 3 short answer questions regarding multiples.
Texas Instruments
Texas Instruments: Magic Nines
In this activity, students compute multiples of 9, 99, 999, and so forth, search for patterns in the products, and write generalizations of those patterns.
NumberNut
Number Nut: Multiplication: Multiplication of Three, Seven, and Nine
Quiz providing practice in multiplying by three, seven, and nine.