Examples with solutions for Divisibility Rules for 2, 4 and 10: Complete the missing numbers

Exercise #1

Complete the number so that it is divisible by 10 without a remainder:

52  52\text{ }_—

Video Solution

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Understand the requirement for divisibility by 10.
  • Apply the divisibility rule.
  • Verify against the given choices.

Now, let's work through each step:
Step 1: The problem asks to complete the number 52  52\text{ }_— so that it is divisible by 10 without a remainder. This means we need the last digit to be 0.
Step 2: According to the divisibility rule for 10, a number must end in 0 to be divisible by 10. Therefore, the last digit must be 0.
Step 3: Among the choices provided, only choice 1 (0 0 ) makes 520 520 divisible by 10, as 520÷10=52 520 \div 10 = 52 with a remainder of 0.

Therefore, the correct digit that completes the number as divisible by 10 is 0.

Answer

0

Exercise #2

Complete the number so that it is divisible by 10 without a remainder:

13? 13\text{?}

Video Solution

Step-by-Step Solution

To determine the missing number that makes 13? 13? divisible by 10, we must consider the divisibility rule for 10: A number is divisible by 10 if its last digit is 0. Therefore, for the number 13? 13? to be divisible by 10, ? must be 0.

We examine the answer choices:

  • Choice 1: 1. If ? is 1, the number 131 131 is not divisible by 10.
  • Choice 2: 2. If ? is 2, the number 132 132 is not divisible by 10.
  • Choice 3: 3. If ? is 3, the number 133 133 is not divisible by 10.
  • Choice 4: All answers are incorrect. The number should be 130 130 to be divisible by 10.

Upon examining the choices, since none corresponds to a digit of 0, the correct answer is indicated by Choice 4: All answers are incorrect.

Answer

All answers are incorrect.

Exercise #3

Complete the number so that it is divisible by 10 without a remainder:

51 — — 51\text{ }_{—\text{ —}}

Video Solution

Step-by-Step Solution

To solve this problem, we'll focus on ensuring divisibility by 10 for the given number 51 — — 51\text{ }_{—\text{ —}} .

The divisibility rule for 10 states that a number must end with the digit 0 to be divisible by 10.

Thus, the missing digits should form a number that ends in 0. Given the partial number 51 1 — 51\text{ }_{1\text{ —}} , we need to check potential combinations that satisfy this rule.

  • Evaluation of the required final digit: Only the digit 0 satisfies the condition for divisibility by 10, meaning the complete number should be 51y0 51y0 where y y is any digit.

Hence, the missing sequence to ensure divisibility by 10 is 1,0 1, 0 . Therefore, 51 1 0 51\text{ }_{1\text{ }0} is the solution.

Returning to the choices provided, the correct answer is choice 1: 1,0 1, 0 .

To conclude, the number is completed as 5110 5110 , which is divisible by 10.

Answer

1, 0

Exercise #4

Complete the numbers to obtain a number divisible by 2 without remainder.

214  214\text{ }_—

Video Solution

Step-by-Step Solution

1. The problem is asking to fill in the blank in the number 214_ with a single digit so that the complete number is divisible by 2. 2. To determine divisibility by 2, the number must end in an even digit (0, 2, 4, 6, or 8). 3. We will evaluate the given choices to see which digits can complete the number to meet this criteria. 4. The rule for divisibility by 2 states that if a number ends in an even digit, it is divisible by 2. 5. We will check each provided option to confirm divisibility. 6. Steps include checking if the number formed with each potential digit is divisible by 2. 7. Assumptions: None required beyond the divisibility rule itself. 8. This is a straightforward application of the divisibility rule; no complex decomposition is necessary. 9. There are no special conditions; any even number from the provided choices will suffice. 10. Review each choice to see if it fits, confirming there is no required explanation of incorrect options as per instructions. 11. Compare each choice against the divisibility rule. 12. Common mistakes might include not understanding the even number criteria. 13. Changing the last digit affects whether the number is even and hence divisible by 2.

To solve this problem, we need to ensure that the complete number is divisible by 2. According to the rules of divisibility for 2, a number is divisible by 2 if its last digit is even. Therefore, we need to select a digit to replace the blank that will result in an even number when appended to 214.

Let's evaluate the provided choices:

  • Choice 1: 2144 – The number ends in 4, which is even. So, 2144 is divisible by 2.
  • Choice 2: 2146 – The number ends in 6, which is even. So, 2146 is divisible by 2.
  • Choice 3: 2148 – The number ends in 8, which is even. So, 2148 is divisible by 2.
  • Choice 4: "All answers are correct" – Since all proposed numbers (2144, 2146, 2148) end in even digits, they are each divisible by 2.

Based on these evaluations, all individual choices result in a number that is divisible by 2.

Therefore, the correct answer is: All answers are correct.

Answer

All answers are correct

Exercise #5

Complete the numbers to obtain a number divisible by 2 without remainder.

105  105\text{ }_—

Video Solution

Step-by-Step Solution

To solve this problem, we need to apply the rule of divisibility by 2, which states that a number is divisible by 2 if its last digit is an even number.

Let's consider the possible digits for the underscore: 11, 55, 33, and 88.

  • If we insert 11, the number becomes 10511051, which ends in an odd digit, not divisible by 2.
  • If we insert 55, the number becomes 10551055, which ends in an odd digit, not divisible by 2.
  • If we insert 33, the number becomes 10531053, which ends in an odd digit, not divisible by 2.
  • If we insert 88, the number becomes 10581058, which ends in an even digit, divisible by 2.

Since the correct last digit that makes the number divisible by 2 is an even number, the solution to the problem is inserting 88.

Therefore, the solution to the problem is 88.

Answer

8

Exercise #6

Complete the numbers to obtain a number divisible by 2 without remainder.

62 —  62\text{ }_{—\text{ }}

Video Solution

Step-by-Step Solution

To solve this problem, we identify the numbers that can make 62  62\text{ }_{—} divisible by 2:

  • A number is divisible by 2 if its last digit is even.
  • In our choices, the even numbers are 0 0 , as it satisfies the divisibility rule for 2.

Substitute the even number:

  • Try 0 0 : The number becomes 620 620 .
  • 620÷2=310 620 \div 2 = 310 , which is an integer showing 620 620 is divisible by 2.

Therefore, the correct digit to ensure 62  62\text{ }_{—} is divisible by 2 is 0.

Answer

0

Exercise #7

Complete the numbers to obtain a number divisible by 2 without remainder.

512  512\text{ }_—

Video Solution

Step-by-Step Solution

To solve this problem, we'll identify which digit can be placed in the blank space to make the number divisible by 2.

Step 1: Review the divisibility rule for 2.
A number is divisible by 2 if its last digit is even.

Step 2: Evaluate each possible choice for the blank in 512_. 512\_.

  • Choice 1: If we fill the blank with 1, the number becomes 5121, which ends with 1, an odd number. This is not divisible by 2.
  • Choice 2: If we fill the blank with 2, the number becomes 5122, which ends with 2, an even number. This number is divisible by 2.
  • Choice 3: If we fill the blank with 3, the number becomes 5123, which ends with 3, an odd number. This is not divisible by 2.
  • Choice 4: If we fill the blank with 5, the number becomes 5125, which ends with 5, an odd number. This is not divisible by 2.

Conclusion: Among all choices, only when the blank is filled with 2, the resulting number 5122 is divisible by 2.

Therefore, the correct answer is 22.

Answer

2

Exercise #8

Complete the number so that it is divisible by 4 without a remainder:

213 — 2 213\text{ }_{—\text{ }}2

Video Solution

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Identify the rule for divisibility by 4.

  • Step 2: Apply this rule to the number — 2 _{—\text{ }}2 .

  • Step 3: Test each possible digit for the missing number to find a two-digit number divisible by 4.

Now, let's work through each step:
Step 1: The divisibility rule for 4 is that a number is divisible by 4 if the last two digits form a number divisible by 4.
Step 2: In the number 213 — 2213\text{ }_{—\text{ }}2, the last two digits are _{\—\text{ }}2. We want this two-digit number to be divisible by 4.
Step 3: Test the potential digits for blank using the choices given:

  • If the blank is 0, the last two digits are 02, which is divisible by 4. But this isn't provided as a solution in the context.

  • If the blank is 2, the last two digits are 22, which is not divisible by 4.

  • If the blank is 3, the last two digits are 32, which is divisible by 4.

  • If the blank is 4, the last two digits are 42, which is not divisible by 4.

Checking through these options shows that placing a 3 in the blank makes the number divisible by 4.

Therefore, the solution to the problem is 3 3 .

Answer

3

Exercise #9

Complete the number so that it is divisible by 4 without a remainder:

54216  54216\text{ }_—

Video Solution

Step-by-Step Solution

To solve this problem, we need to complete the number 54216_54216\_ so that the entire number is divisible by 4. The rule for divisibility by 4 is that the number formed by its last two digits must be divisible by 4.

Let's try each of the given possibilities for the missing digit:

  • For 0: Make the number 542160542160. Last two digits are 60. Check divisibility: 60÷4=1560 \div 4 = 15, remainder 0.
  • For 1: Make the number 542161542161. Last two digits are 61. Check divisibility: 61÷4=15.2561 \div 4 = 15.25, remainder is not 0.
  • For 2: Make the number 542162542162. Last two digits are 62. Check divisibility: 62÷4=15.562 \div 4 = 15.5, remainder is not 0.
  • For 3: Make the number 542163542163. Last two digits are 63. Check divisibility: 63÷4=15.7563 \div 4 = 15.75, remainder is not 0.

Out of the available options, only appending 0 to make the number 542160542160 satisfies the condition, as 60 is divisible by 4.

Therefore, the digit that should replace the missing underscore to make the number divisible by 4 is 0.

Answer

0

Exercise #10

Complete the number so that it is divisible by 4 without a remainder:

21 — — 21\text{ }_{—\text{ —}}

Video Solution

Step-by-Step Solution

To solve the problem, we will ensure the two-digit number formed from the missing blanks at the end of 21 is divisible by 4. This requires performing the following steps:

  • Step 1: Identify combinations for the blanks. Since this is a two-digit number, consider each combination within the range of numbers provided.
  • Step 2: Check divisibility. Once the numbers are identified, check if they are divisible by 4.
  • Step 3: Validate the correct number. The rule is that it must divide evenly with no remainder.

Numbers formed by potential combinations from the given choices are:
- 212212, 214214

Now, let's check each of these numbers:

  • 212212: Dividing 212 by 4 gives 212÷4=53 212 \div 4 = 53 . This is an integer, meaning 212 is divisible by 4.
  • 214214: Dividing 214 by 4 gives 214÷4=53.5 214 \div 4 = 53.5 . This is not an integer, hence 214 is not divisible by 4.

After evaluation, the number 212212 is divisible by 4.

The numbers that fill the blanks and ensure divisibility by 4 are 2, 4.

Answer

2, 4