Consider these statements: (а) Only the last two digits matter when deciding if a given number is divisible by 4. Class 6

Consider these statements: (а) Only the last two digits matter when deciding if a given number is divisible by 4. Class 6

Question 1.

Consider these statements: Class 6

(а) Only the last two digits matter when deciding if a given number is divisible by 4.

(b) If the number formed by the last two digits is divisible by 4, then the original number is divisible by 4.

(c) If the original number is divisible by 4, then the number formed by the last two digits is divisible by 4.

Do you agree? Why or why not?

Solution:

Yes, I agree.

Question 2.

Find numbers between 120 and 140 that are divisible by 8. Also find numbers between 1120 and 1140, and 3120 and 3140, that are divisible by 8. What do you observe? Class 6

Solution:

Such numbers between 120 and 140 are 128 and 136. Between 1120 and 1140, such numbers are 1128 and 1136. Between 3120 and 3140, such numbers are 3128 and 3136. We observe that 128 and 136 are divisible by 8.