Explain to a student how to use signed counters to evaluate this problem: -3 + 2

The signed counters shown BEST represents the integer problem:

IS 510,505,050,999,990 DIVISIBLE BY 5?

IS 320,230,320,132 DIVISIBLE BY 6?

Classify 129 as a prime or composite number.

Which of the following is NOT in the fact family of 4 | 24?

List all the factors of 54.

Fill in the blank to make a true statement. 15 is a _____ of 5.

Which of the following is NOT in the fact family of 4 | 28?

Prime factor 40.