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Grade 4

CCSS Math Standard: 4.OA.4

Gain familiarity with factors and multiples. Find all factor pairs for a whole number in the range 1-100. Recognize that a whole number is a multiple of each of its factors. Determine whether a given whole number in the range 1-100 is a multiple of a given one-digit number. Determine whether a given whole number in the range 1-100 is prime or composite.

Factors and Codes: First Names (Episode 2)

Scrambled up somewhere in 161,000 is a first name. Can you find it!?

Factors and Codes (Episode 1)

Let's use factors to encode and decode words.

Fizz Buzz: A Counting and Divisibility Game

Ready for a tricky counting and divisibility game?

Math Curiosity: Klauber’s Triangle

In 1932, a leading authority on rattlesnakes, Laurence Klauber, discovered a startling pattern within a triangle of primes.

Why Is Our Calendar So Weird!?

Why are there 12 months? Why don't weeks fit into months evenly? Why don't weeks fit into the year evenly? What's going on with the calendar!