Multiply Multiples of 10 Using Place Value Units
Multiply Multiples of 10 Using Place Value Units is a Grade 5 math skill from Eureka Math that teaches students to multiply numbers like 30 x 400 by treating them as place value units. Students learn that 3 tens x 4 hundreds = 12 thousands, using unit language to simplify multi-digit multiplication. This place value approach builds conceptual understanding before the standard algorithm.
Key Concepts
To multiply multiples of 10, express each factor as a digit times a place value unit. The final product is found by multiplying the digits and multiplying the place value units separately, then combining the results. $$(a \times \text{unit} 1) \times (b \times \text{unit} 2) = (a \times b) \times (\text{unit} 1 \times \text{unit} 2)$$.
Common Questions
How do you multiply multiples of 10 using place value units?
Express each number as a place value unit: 30 = 3 tens, 400 = 4 hundreds. Then multiply the units: 3 x 4 = 12, and tens x hundreds = thousands, so 30 x 400 = 12,000.
What are place value units in Grade 5 multiplication?
Place value units describe numbers using unit language: tens, hundreds, thousands, etc. Multiplying 50 x 60 becomes 5 tens x 6 tens = 30 hundreds = 3,000.
Why use place value unit language for multiplication in Grade 5?
Place value unit language helps students understand why products are larger or smaller by connecting the multiplication to the structure of the base-10 number system.
What Eureka Math Grade 5 chapter covers multiplying multiples of 10?
Eureka Math Grade 5 Chapter 7 covers mental strategies for multi-digit multiplication, including multiplying multiples of 10 and 100 using place value units.
How does this strategy help with mental math multiplication?
By thinking of numbers as place value units, students can break multi-digit multiplication into simpler steps: multiply the non-zero digits, then determine the resulting unit (tens, hundreds, etc.).