​Chapter 2: Multiply by 1-Digit Numbers

In Chapter 2 students will:

• Relate multiplication equations and comparison statement
• solve problems involving multiplicative comparison & additive comparison
• Multiply 10s, 100s, & 1,000s by whole numbers through ten
• Estimate products & determine if exact answers to multiplication problems are reasonable
• Multiply numbers using the Distributive Property
• Use expanded form to multiply a multidigit number by a 1-digit number
• Use place value & partial products to multiply a multidigit number by a 1-digit number
• Use mental math & properties to multiply a multidigit number by a 1-digit number
• Multiply a multidigit number by a 1-digit number with regrouping
• Recognize & solve multistep problems using equations

Chapter 2 videos:

Lesson 2.1 Multiplication Comparisons (CC.4.OA.1)

Lesson 2.2 Comparison Problems (CC.4.OA.2)

Lesson 2.3 Multiply 10s, 100s, & 1,000s (CC.4.NBT.5)

Lesson 2.4 Estimate Products (CC.4.NBT.5)

Lesson 2.5 Multiply Using the Distributive Property (CC.4.NBT.5)

Lesson 2.6 Multiply Using Expanded Form (CC.4.NBT.5)

Lesson 2.7 Multiply Using Partial Products (CC.4.NBT.5)

Lesson 2.8 Multiply Using Mental Math (CC.4.NBT.5)

Lesson 2.9 Multistep Multiplication Problems (CC.4.OA.3)

Lesson 2.10 Multiply 2-Digit Numbers with Regrouping (CC.4.NBT.5)

Lesson 2.11 Multiply 3 & 4-Digit Numbers with Regrouping (CC.4.NBT.5)

Lesson 2.12 Solve Multistep Problems Using Equations (CC.4.OA.3)

Vocabulary:

• multiplication- Putting together equal groups to find a total or the product
• factor – a number that is multiplied by another number to find a product
• product – the answer to a multiplication problem
• multiple- The products that can be produced when multiplying by a given number, or by skip counting
• Distributive Property of Multiplication – the property that states that multiplying a sum by a number that is the same as multiplying each added by the number and them adding the products
• ex: 5x13 = (5x10) + (5x3)
• 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
• expanded form – a way to write numbers by showing the value of each digit
• 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)
• Commutative Property - Property that states that the order in which two numbers are multiplied does not change the product.
• ex: 6x3=3x6
• estimate – a number close to an exact amount
• round – to replace a number with another number that tells about how many or how much
• array- A way of representing a number sequence in equal columns and rows

Chapter 2 Standards: Operations and Algebraic Thinking; Number and Operations in Base Ten

Use the four operations with whole numbers to solve problems;

CC.4.OA.1 Interpret a multiplication equation as a comparison, e.g., interpret 35 = 5x7 as a statement that 35 is 5 times as many as 7 and 7 times as many as 5. Represent verbal statements of multiplicative comparisons as multiplication equations.

Use the four operations with whole numbers to solve problems;

CC.4.OA.2 Multiply or divide to solve word problems involving multiplicative comparison, e.g., by using drawings and equations with a symbol for the unknown number to represent the problem, distinguishing multiplicative comparison from additive comparison.

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.