Download Presentation
## 5th Grade Division

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -

**5th Grade**Division Mrs. Berish**Setting the PowerPoint View**• Use Normal View for the Interactive Elements • To use the interactive elements in this presentation, do not select the Slide Show view. Instead, select Normal view and follow these steps to set the view as large as possible: • On the View menu, select Normal. • Close the Slides tab on the left. • In the upper right corner next to the Help button, click the ^ to minimize the ribbon at the top of the screen. • On the View menu, confirm that Ruler is deselected. • On the View tab, click Fit to Window. • Use Slide Show View to Administer Assessment Items • To administer the numbered assessment items in this presentation, use the Slide Show view. (See Slide 12 for an example.)**Click on the topic to**go to that section Division Unit Topics • Divisibility Rules • Patterns in Multiplication and Division • Division of Whole Numbers • Division of Decimals**Divisibility Rules**Click to return to the table of contents**Divisible**When one number can be divided by another and the result is an exact whole number. five three Example: 15 is divisible by 3 because 15 ÷ 3 = 5 exactly BUT 9 is not divisible by 2 because 9 ÷ 2 is 4 with one left over.**Divisibility**A number is divisible by another number when the remainder is 0. There are rules to tell if a number is divisible by certain other numbers.**Divisibility Rules**Look at the last digit in the Ones Place! 2 Last digit is even-0,2,4,6,8 5 Last digit is 5 OR 0 10 Last digit is 0 Check the Sum! 3 Sum of digits is divisible by 3 6 Number is divisible by 3 AND 2 9 Sum of digits is divisible by 9 Look at Last Digits 4 Last 2 digits form a number divisible by 4**x**Let's Practice! Is 34 divisible by 2? Yes, because the digit in the ones place is an even number. Therefore, 34 / 2 = 17 Is 1,075 divisible by 5? Yes because the digit in the ones place is a 5. Therefore, 1,075 / 5 = 215 Is 740 divisible by 10? Yes, because the digit in the ones place is a 0. Therefore, 740 / 10 = 74**Is 258 divisible by 3?**Yes, because the sum of its digits is divisible by 3. 2 + 5 + 8 = 15 Look 15 / 3 = 5 Therefore, 258 / 3 = 86 Is 193 divisible by 6? Yes, because the sum of its digits is divisible by 3 AND 2. 1 + 9 + 2 = 12 Look 12 /3 = 4 Therefore, 192 / 6 = 32 x**Is 6,237 divisible by 9?**Yes, because the sum of its digits is divisible by 9. 6 + 2 + 3 + 7 = 18 Look 18 / 9 = 2 Therefore, 6,237 /9=693 Is 520 divisible by 4? Yes, because the number made by the last two digits is divisible by 4. 20 / 4 = 5 Therefore, 520 / 4 = 130 x**Is 198 divisible by 2?**1 Yes No**2**Is 315 divisible by 5? Yes No**3**Is 483 divisible by 3? Yes No**4**294 divisible by 6? True False**5**3,926 is divisible by 9 True False**Some numbers are divisible by more than one digit.**Using the Divisibility Rules, let's practice. 18 is divisible by how many digits? Let's see if your choices are correct. Did you guess 2, 3, 6 and 9? 165 is divisible by how many digits? Let's see if your choices are correct. Did you guess 3 and 5? Click Click**28 is divisible by how many digits?**Let's see if your choices are correct. Did you guess 2 and 4? 530 is divisible by how many digits? Let's see if your choices are correct. Did you guess 2, 5, and 10? Now it's your turn...... Click Click**Complete the table using the Divisibility Rules**(Click on the cell to reveal the answer) • 1,218**6**What are all the digits 15 is divisible by?**7**What are all the digits 36 is divisible by?**8**What are all the digits 1,422 are divisible by?**9**What are all the digits 240 are divisible by?**10**What are all the digits 64 is divisible by?**Patterns in Multiplication and Division**Click to return to the table of contents**Powers of 10**Numbers like 10, 100 and 1,000 are called powers of 10. They are numbers that can be written as products of tens. 100 can be written as 10 x 10 or 102. 1,000 can be written as 10 x 10 x 10 or 103.**103**The raised digit is called the exponent. The exponent tells how many tens are multiplied.**A number written with an exponent, like 103, is in**exponential notation. A number written in a more familiar way, like 1,000 is in standard notation.**Powers of 10 from ten to one million.**(greater than 1) Powers of 10 Standard Product Exponential Notation of 10s Notation 10 10 101 100 10 x 10 102 1,000 10 x 10 x 10 103 10,000 10 x 10 x 10 x 10 10 100,000 10 x 10 x 10 x 10 x 10 105 1,000,000 10 x 10 x 10 x 10 x 10 x 10 106 4**It is easy to MULTIPLY a whole number by a power of 10.**Add on as many 0s as appear in the power of 10. Examples: 28 x 10 = 280 Add on one 0 28 x 100 = 2,800 Add on two 0s 28 x 1,000 = 28,000 Add on three 0s**If you have memorized the basic multiplication facts, you**can solve problems mentally. Use a pattern when multiplying by powers of 10. steps 1. Multiply the digits to the left of the zeros in each factor. 50 x 100 5 x 1 = 5 2. Count the number of zeros in each factor. 50 x 100 3. Write the same number of zeros in the product. 5,000 50 x 100 = 5,000 50 x 100 5,000**60 x 400 = _______**steps 1. Multiply the digits to the left of the zeros in each factor. 6 x 4 = 24 2. Count the number of zeros in each factor. 3. Write the same number of zeros in the product.**60 x 400 = _______**steps 1. Multiply the digits to the left of the zeros in each factor. 6 x 4 = 24 2. Count the number of zeros in each factor. 60 x 400 3. Write the same number of zeros in the product.**60 x 400 = _______**steps 1. Multiply the digits to the left of the zeros in each factor. 6 x 4 = 24 2. Count the number of zeros in each factor. 60 x 400 3. Write the same number of zeros in the product. 60 x 400 = 24,000**500 x 70,000 = _______**steps 1. Multiply the digits to the left of the zeros in each factor. 5 x 7 = 35 2. Count the number of zeros in each factor. 3. Write the same number of zeros in the product.**500 x 70,000 = _______**steps 1. Multiply the digits to the left of the zeros in each factor. 5 x 7 = 35 2. Count the number of zeros in each factor. 500 x 70,000 3. Write the same number of zeros in the product.**500 x 70,000 = _______**Steps 1. Multiply the digits to the left of the zeros in each factor. 5 x 7 = 35 2. Count the number of zeros in each factor. 500 x 70,000 3. Write the same number of zeros in the product. 500 x 70,000 = 35,000,000**Your Turn....**Write a rule. Input Output rule 15,000 50 2,100 7 90,000 300 6,000 20**Write a rule.**Input Output 18,000 rule 20 6,300 7 8,100,000 9,000 72,000 80**30 x 10 =**11**12**800 x 1,000 =**13**900 x 10,000 =**14**700 x 5,100 =**15**70 x 8,000 =**16**40 x 500 =**17**1,200 x 3,000 =**18**35 x 1,000 =**It is easy to DIVIDE a whole number by a power of 10.**Take off as many 0s as appear in the power of 10. Example: 42,000 / 10 = 4,200 Take off one 0 42,000 / 100 = 420 Take off two 0s 42,000 / 1,000 = 42 Take off three 0s**If you have memorized the basic division facts, you can**solve problems mentally. Use a pattern when dividing by powers of 10. 60 / 10 = 60 / 10 = 6 steps Cross out the same number of 0s in the dividend as in the divisor. 2. Complete the division fact.**More Examples:**8,000 / 10 8,000 / 10 = 800 700 / 10 700 / 10 = 70 9,000 / 100 9,000 / 100 = 90**This pattern can be used in other problems**. 120 / 30 44,600 / 200 44,600 / 200 = 223 1,400 / 700 1,400 / 700 = 2 120 / 30 = 4