1 / 9

Multiplication

Multiplication. Multiplying by 10. When you multiply by 10, all the digits move one place to the left. 4. 5. 0. Remember to put a zero in the empty place. Remember: A quick way to multiply a whole number by 10 is to put a zero on the end. Multiplying by 100.

raymondrivera
Download Presentation

Multiplication

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Multiplication

  2. Multiplying by 10 When you multiply by 10, all the digits move one place to the left. 4 5 0 Remember to put a zero in the empty place. Remember: A quick way to multiply a whole number by 10 is to put a zero on the end.

  3. Multiplying by 100 When you multiply by 100, all the digits move two places to the left. 4 5 0 0 Fill up the two empty places with two zeros. Remember: A quick way to multiply a whole number by 100 is to put two zeros on the end.

  4. Multiplying large numbers Look at this example: Step 1: Start with the units. 5 x 7 = 35. Put 5 in the units column and carry the 3 into the tens. 1 1 8 5 3 1 Step 2: Now the tens. 5 x 3 = 15. Add the 3 you carried to get 18. Put 8 in the tens column and carry the 1 into the hundreds. Step 3: Now the hundreds. 5 x 2 = 10. Add the 1 you carried to get 11. Write 1 in the hundreds column and 1 in the thousands.

  5. Multiplying large numbers Now look at this example: Step 1: Multiply 237 by 5 just like we did last time. Step 2: The 4 is in the tens column so has the value 40. x 1 3 1 8 5 1 To multiply by 40, we multiply by both 10 and 4. + 1 2 9 4 8 0 Put a zero in the units column to multiply by 10. 1 0 6 6 5 1 Now multiply by 4. Step 3: Add to get your answer.

  6. Multiplying large numbers The two most common mistakes. x 3 1 1 8 5 1 1. Forgetting this zero. + 1 2 9 4 8 0 1 0 6 6 5 1 2. Getting the carrying figures muddled up – keep them separate.

  7. Lattice method Here is another way to multiply 237 x 45. We are multiplying a three digit number by a two digit number, so draw a table with 3 columns and two rows like this: Now put 237 across the top and 45 down the right hand side. 7 2 3 4 5

  8. Lattice method Now fill in the squares by multiplying. 2 x 4 = 8 (no tens and8 units) 3 x 4 = 12 7 x 4 = 28 7 2 3 2 0 1 4 8 8 2 1 3 1 5 5 5 0 7 x 5 = 35 2 x 5 = 10 3 x 5 = 15

  9. Lattice method Now add up following the diagonal lines: 7 2 3 2 0 1 4 8 8 2 1 1 3 5 5 5 0 1 1 6 1 0 6 5 Don’t forget the 1 you’re carrying! So 237 x 45 = 10665

More Related