5th Grade · Math · 5.NBT.B.5

Multiplying In Parts Lesson Plan for 5th Grade

A ready-to-teach multiplying in parts lesson for 5th Grade. Everything below is classroom-tested structure: an objective, a 45-minute sequence, a way to check who got it, and 6 printable practice pages.

Approximately 45 minutes

Learning objective

Break factors into expanded form to multiply in parts
Use the distributive property to simplify large multiplication problems
Combine partial products to find the final product accurately

Materials

Mental math: Multiplying 1 digit by 2 digits - Chill Ice Cream
Mental Math: Multiplying 1 digit by 2 digits - Cool Pineapple
Multiply 2 by 4 digit numbers - Dove
Mental Math: Multiplying 1 digit by 2 digits - Slick Coffee
Mental Math: Multiplying 1 digit by 2 digits - Dreamy Tablet
Multiply 2 by 4 digits - Catrina
Pencils, and whiteboard space for the modeled examples

Lesson steps

1. Warm up together (5 min)
Open with three quick mental problems on multiplying in parts, hands down, answers called out together. You are checking who has recall and who is reconstructing every time.
2. Model it (I do) (10 min)
Solve two multiplying in parts problems on the board, narrating the step most students skip. Then solve one wrong and ask the class to find where it broke.
3. Practice together (we do) (10 min)
Work three more problems as a class. Ask a different student to supply each step rather than the whole answer. If a step stalls, drop back to concrete objects or a drawing before moving on.
4. Independent practice (you do) (15 min)
Hand out "Mental math: Multiplying 1 digit by 2 digits - Chill Ice Cream". Students work independently while you circulate. Note who is fluent, who is counting on fingers, and who has not started, because that grouping drives tomorrow's small group.
5. Close the loop (5 min)
Pull the class back. Ask one student to explain a problem they got right and one to name something that is still confusing. End on the confusion, not the success, so students learn that naming a gap is normal.

Check for understanding

Collect the practice pages and sort them into three piles: fluent, developing, and not yet. Any student in the third pile needs multiplying in parts retaught in a small group before the class moves on.

Differentiation

Extra support. Students who stall: pull them into a small group and rebuild multiplying in parts with concrete materials or a simpler text before asking for the written work again. Do not send the page home as homework, it will just rehearse the misunderstanding.

Extension. Students who finish early: ask them to write their own multiplying in parts problem for a partner to solve, then check the partner's work. Creating a problem is harder than solving one and it surfaces whether they really understand multiplying in parts.

Skills covered in this lesson

Multiplying in parts · Multiplication

Questions teachers ask about teaching multiplying in parts

What is multiplying in parts (partial products) in fifth grade?

Multiplying in parts, also called the partial products method, breaks each factor into expanded form before multiplying. For example, 34 × 27 becomes (30 + 4) × (20 + 7), producing four partial products that are then added together. This method builds on the distributive property (CCSS 5.NBT.B.5) and deepens understanding of the standard algorithm.

Why is the partial products method useful for fifth graders?

Partial products make the place value reasoning behind multiplication visible, helping students understand why the standard algorithm works rather than just following steps. CCSS 5.NBT.B.5 requires fluency with multi-digit multiplication using the standard algorithm, and partial products provide the conceptual bridge. Students who understand partial products make fewer place value errors with larger numbers.

How does multiplying in parts connect to the distributive property?

The distributive property states that a × (b + c) = a × b + a × c. Multiplying in parts applies this property by distributing each digit of both factors. Worksheets that show the area model alongside partial products equations help students see the connection between visual and symbolic representations of the distributive property.