In this lesson we used place-value understandings and patterns to mentally multiply whole numbers and powers of 10. We used exponents and place-value to understand how many "tens" were being multiplied, which told us what place our answer should be in (sometimes we think, "multiply the parts you know, then add in the zeros").

Helpful Videos:

• Multiplying Whole Numbers by Powers of Ten | Math with Mr. J (8:30)

In this lesson we reviewed how to multiply larger numbers by a one-digit number, focusing on regrouping and lining up our place values. We reviewed both the area model and the standard algorithm.

Helpful Videos:

• 2-digit by 1-digit | Multiplication | Maths with Mrs. B (3:39)

• Multiplying: 2 digits times 1 digit (with carrying) | Khan Academy (2:08)

In this lesson we continued our use of the standard algorithm to multiply larger numbers by a two-digit number. Remember, always put the smaller number on the bottom so there are fewer partial products.

Helpful Videos:

• 3-Digit by 2-Digit Multiplication | Math with Mr. J (5:02)

In this lesson we used properties and the standard algorithm for multiplication to find the product of multi-digit numbers.

Helpful Videos:

• Multiplication: A Step-By-Step Review | Math with Mr. J (20:23 - Includes single, double, and triple-digit multiplication)

In this lesson we learned to critique the reasoning of others by asking questions, looking for flaws, and using prior knowledge of estimating products.

Helpful Videos:

• Math Topic 3-9 Problem Solving: Critique Reasoning | enVision Math (3:32)