Chapter 3: Multiply 2-Digit Numbers

Chapter 3: Multiply 2-Digit Numbers

In Chapter 3 students will:

• Use place value and multiplication properties to multiply 2-digit numbers by a 2-digit tens

• Estimate products by rounding or using compatible numbers

• Use place value, area models, and partial products to multiply 2-digits by 2-digits

• Use regrouping to multiply 2-digits by 2-digits

• Solve multistep multiplication word problems

Vocabulary:

• Associative Property of Multiplication: - the property that states that you can group factors in different ways and get the same product

• ex: (6x10)x10 = 6x(10x10)

• factor – a number that is multiplied by another number to find a product

• product – the answer to a multiplication problem

• compatible numbers - numbers that are easy to compute mentally and work well together

• ex: 25 & 4

• partial product – a method of multiplying in which the ones, tens, hundreds, and so on are multiplied separately and then the products are added together

• estimate – a number close to an exact amount

• round – to replace a number with another number that tells about how many or how much; 39 rounds to 40, 128 rounds to 100

Chapter 3 videos:

Lesson 3.1 Multiply by Tens (CC.4.NBT.5)

Lesson 3.2 Estimate Products (CC.4.NBT.5)

Lesson 3.3 Area Models and Partial Products (CC.4.NBT.5)

Lesson 3.4 Multiply Using Partial Products (CC.4.NBT.5)

Lesson 3.5 Multiply with Regrouping (CC.4.NBT.5)

Lesson 3.6 Choose a Multiplication Method (CC.4.NBT.5)

Lesson 3.7 Problem Solving - Multiply 2-Digit Numbers (CC.4.OA.3)

Chapter 3 Standards: Operations and Algebraic Thinking; Number and Operations in Base Ten

Use the four operations with whole numbers to solve problems;

CC.4.OA.3 Solve multistep word problems posed with whole numbers and having whole-number answers using the four operations, including problems in which remainders must be interpreted. Represent these problems using equations with a letter standing for the unknown quantity. Assess the reasonableness of answers using mental computation and estimation strategies including rounding.

Use place value understanding and properties of operations to perform

multi-digit arithmetic;

CC.4.NBT.5 Multiply a whole number up to four digits by a one-digit whole number, and multiply two two-digit numbers, using strategies based on place value and the properties of operations. Illustrate and explain the calculation by using equations, rectangular arrays, and/or area models.