Today we learned how to multiply using partial products. This involved using the distributive property. When talking about the distributive property, we use grids or models to help organize our work.
In our last unit, we learned how to write numbers in their expanded form . For example, if I have the number 470....I know I can expand or stretch out that number to 400+70+0. When given a multiplication problem with a multi-digit number, we learned how to expand that multi-digit number to make multiplication easier. This lesson dealt with multiplying using the distributive property. We used a grid to help us make our model. This grid allowed us to see how the numbers are distributed and making numbers easier to multiply. This math lesson involves students knowing how to round numbers to their largest place value and then multiplying the rounded number to estimate the product. With these problems, students will only round the multi-digit number in the equation. For example, if they have the equation: 4 x 287, then they will only round the number 287 to it's largest place value, which in this case is the hundreds. To round to the nearest hundreds, students must find the hundreds place, look next door, and think to themselves: 5 or more, add 1 more...4 or less, let it rest. In this case, the 2 looks to the 8, in which the 8 tells the 2 to round up (add 1 more). Therefore, 287 rounded to the nearest hundred is 300. The estimated equation is now 4 x 300. Students will use their knowledge of lesson 2.3 to help them solve that equation. Refer back to that video, if you need a reminder on how to solve those types of equations. The answer is then the estimated product. Lesson 2.3 involved having the students use their knowledge of basic multiplication facts to help them solve equations that dealt with multiplying a one digit number by 10, 100, and 1,000. Students learned that if they know the answer to the basic math fact, then they can easily multiply by 10, 100, and 1,000 by just simply tacking on the number of zeros. It is important that the students continue to practice their basic math facts at home, as this will greatly help with their math lessons in this unit. Please feel free to contact me if you would like me to send home a pack of flashcards for you to keep at home. |
Mrs. MarshKindergarten and 4th Grade learning support teacher at Schnecksville Elementary School. Archives
October 2017
Categories |