Lattice and Partial Products Methods

The video tutorial introduces third graders to multiplying two-digit numbers using the lattice method. It begins with a detailed explanation of the lattice method, using the example of 39 * 48. The teacher guides students through the steps of setting up the lattice, performing the multiplications, and adding the results to find the final answer. The tutorial then moves on to a new example, 20 * 38, demonstrating the lattice method again. Finally, the teacher introduces the partial products algorithm as an alternative method for multiplying two-digit numbers, showing how it yields the same result as the lattice method.

What is the lattice method primarily used for?

• Subtracting numbers

• Dividing numbers

• Adding numbers

• Multiplying numbers

In the lattice method, what is the first step when multiplying 39 by 48?

• Subtract the numbers

• Write 39 and 48 on opposite sides

• Add the numbers

• Divide the numbers

What is the result of multiplying 4 by 9 in the lattice method example?

• 18

• 27

• 36

• 45

How do you handle the middle section in the lattice method when adding partial products?

• Ignore it

• Multiply it by 2

• Add the digits together

• Subtract the digits

What is the final result of 39 multiplied by 48 using the lattice method?

• 1,827

• 1,872

• 1,782

• 1,728

In the lattice method example of 20 * 38, what is the result of 3 multiplied by 2?

• 6

• 5

• 4

• 8

What is the result of 8 multiplied by 2 in the lattice method example of 20 * 38?

• 14

• 16

• 12

• 18

What is the final result of 20 multiplied by 38 using the lattice method?

• 760

• 780

• 720

• 800

What is the first step in the partial products algorithm for two-digit multiplication?

• Multiply the tens place first

• Multiply the ones place first

• Add the numbers

• Subtract the numbers

In the partial products algorithm, what is the result of 3 multiplied by 2?

• 7

• 6

• 8

• 5