## Twenty-Four (using the last four digits of phone numbers)

Here are assessments and activities for building foundations for fluency, based on K-5 Common Core Standards.

### Twenty-Four (using the last four digits of phone numbers)

“Twenty Four” (using the last four digits of phone numbers)is a game (activity) based on the game “24”
CCSS fluency benchmark:
2.NBT.5. Fluently add and subtract within 100 using strategies based on place value,
properties of operations, and/or the relationship between addition and subtraction.
3.OA.7: Fluently multiply and divide within 100, using strategies such as the relationship between multiplication and division (e.g., knowing that 8 × 5 = 40, one knows 40 ÷ 5 = 8) or properties of operations. By the end of Grade 3, know from memory all products of two one-digit numbers.
All students in grades five and up can benefit from this activity.
This is a great activity to use in middle school to encourage students to think about numbers, the operations associated with them: addition, subtraction, multiplication, division, exponents, square roots, and factorials. Students are also polishing their fluency with addition, subtraction, multiplication and division facts, through 100 and higher. I like to use phone numbers because they include zero.

Keywords: Addition, Subtraction, Multiplication, Division, Exponents, Factorials, number sense, mental math,

The attached document has complete instructions, activities, and criteria for use.
Attachments
Twenty-Four with last four digits of phone number Directions and Criteria.pdf