Unit 5: Big Numbers, Estimation, and Computation
Check out the Unit 5 Written Assessment below for the goals covered and assessed in Unit 5.
Vocabulary:
Place Value: trillion, billion, million, quadrillion, quintillion, sextillion
Estimation: rough estimate, round, rounding (to a certain place)
Exponents: powers of 10, scientific notation
Vocabulary:
Place Value: trillion, billion, million, quadrillion, quintillion, sextillion
Estimation: rough estimate, round, rounding (to a certain place)
Exponents: powers of 10, scientific notation
Multiplication Facts Galore!
As begin the new year, we are really focusing on making sure that our multiplication and division facts are automatic. Since we are multiplying multidigit numbers, it is extremely important to have the basic facts committed to memory. You can help your child at home by quizzing him/her on basic multiplication facts each night.
I realize that the way I teach multidigit multiplication is different than the way people are traditionally taught. We do learn the traditional algorithm as well, but the goal of the Everyday Mathematics program is to give students a variety of methods so each child can pick the method that works best for him/her. Please watch the following videos to familiarize yourselves with the Partial Products and Lattice multiplication methods so you understand what your child is learning at school.
I realize that the way I teach multidigit multiplication is different than the way people are traditionally taught. We do learn the traditional algorithm as well, but the goal of the Everyday Mathematics program is to give students a variety of methods so each child can pick the method that works best for him/her. Please watch the following videos to familiarize yourselves with the Partial Products and Lattice multiplication methods so you understand what your child is learning at school.
We estimate to make our life easier!!!
Think about going to the grocery store.
Do you think you should add up every single penny you spend? Or would you round $1.99 to $2.00 so you can work with a number that is a little easier to add in your head? By rounding $1.99 to $2.00, you are using estimation! It makes our lives easier to compute nice round numbers. 

Estimating Products

Just like estimating sums, we estimate products to make our lives easier. We also want to estimate so we can make sure that our answer is in the right place value.
For instance, 46 * 87 is a hard problem to do in your head. But if you estimate first, you can do a much easier problem: 50 * 90 which is 5 * 9 = 45 and then add 2 zeros, so my estimate is 4,500. I know that my answer should be in the thousands place because my estimate is in the thousands place. 
Multiplication Algorithms
We are going to teach you several different methods to arrive at the same answer. We do this because some kids prefer multiplying by using the Partial Products method, some like Lattice, and some still like the Traditional algorithm that has been taught for years. We want you to try all the methods, but you will be able to choose your favorite method to solve problems on the test.
Partial Products

Another good reason to learn multiple ways to do something is because you can doublecheck your work. For instance, let's say you used the Traditional algorithm to solve a problem on your test. You could doublecheck your answer by doing the same problem using the Partial Products algorithm. Then you could compare your answers to make sure they match.
Hint: Teachers LOVE it when you show your work and doublecheck your answers! You'll love it too when your grade is higher from making sure you got the correct answers! :) 
Partial Products 
Lattice Multiplication 