Use Strategies and Properties to Multiply by 1-Digit Numbers 3-1: Mental Math: Multiply by Multiples of 10, 100, and 1,000 3-2: Mental Math: Round to Estimate Products 3-3: The Distributive Property 3-4: Mental Math Strategies 3-5: Arrays and Partial Products 3-6: Using Partial Products to Multiply 3-7: Multiply 2- and 3- Digit Numbers by 1-Digit Numbers 3-8: Multiply 4-Digit Numbers by 1-Digit Numbers Topic 3 Lessons 1-8 Use Strategies and Properties to Multiply by 1-Digit Numbers

I can… multiply by multiples of 10, 100, and 1,000 3-1 MENTAL MATH I can… multiply by multiples of 10, 100, and 1,000 Example: Find 3 x 800 Steps: Find the basic fact 3 x 8 =24 Count the zeros in the original problem (2) Add the zeros to the product of the basic fact 2400 Check that your answer is reasonable 800 + 800 + 800 = 2,400 ✓ Remember that as you move from right to left on the place value chart, you are multiplying by 10

I can… estimate products by rounding 3-2 MENTAL MATH: ROUNDING I can… estimate products by rounding Example: Find an estimate for 3 x 1,150 3 Reasonable Estimates: Round 1,150 down to 1,000 → 3 x 1,000 = 3,000 Round 1,150 up to 1,200 → 3 x 1,200 = 3,600 Change 1,150 to 1,100 → 3 x 1,100 = 3,300

I can… use the Distributive Property to Multiply! Example: 7 x 68 Steps: Think how you can break apart the larger number: 68 → 60 + 8 Multiply the other factor, 7, by each of those parts: 7 x 60 = 420 and 7 x 8 = 56 Add the two partial products: 420 + 56 = 476 Check that your answer is reasonable by finding an estimate: 7x70= 490 ✔ my answer is reasonable because 476 is close to 490 How to Show Your Work: 7 x 68 = (7x60) + (7x8) 7 x 68 = 420 + 56 7 x 68 = 476

I can… use mental math strategies to multiply Example #1: 225 x 4 Think: I already know that I can break apart numbers using the distributive property I also know that 4 x 25 equals 100 So, I can solve this problem mentally like this: 200 x 4 = 800 25 x 4 = 100 800 + 100 = 900 → 225 x 4 = 900 Example #2: 2 x 295 Think: 295 is close to 300, and I can easily multiply 2 x 300 in my head (600) I know this is 5 groups of 2 too many though, so I need to subtract 10 from 600. 2 x 295 = 600 -100 which = 590

I can… use tools and multiplication strategies to find products 3-5 Arrays and Partial Products I can… use tools and multiplication strategies to find products

I can… use partial products to multiply large numbers 3-6 Using Partial Products to Multiply I can… use partial products to multiply large numbers

3-7 Multiply 2- and 3- Digit Numbers by 1-Digit Numbers I can… use place value strategies and algorithms to multiply 2-digit and 3-digit numbers Strategy #1: Use Place Value 26 x 8 48 (8 x 6) + 160 (8 x 20) 208 Strategy #2: Use the Standard Algorithm 1 4 26 x 8 208 Multiply the ones (8x6=48) Carry the 4, drop the 8. Multiply the tens (8x2=16). Carry the 1, drop the 6. Regroup.

2 1 3 1,425 x 6 3-8 Multiply 4-Digit Numbers by 1-Digit Numbers 8, 550 I can… multiply large numbers using the steps/strategies as I do with smaller numbers Example: 1,425 x 6 2 1 3 1,425 x 6 8, 550 1,400 x 6 = 8,400 Steps: Multiply the ones. Regroup if needed. Multiple the tens, add any extra tens that were carried over. Regroup if needed. Multiple the hundreds, add any extra hundreds that were carried over. Regroup if needed. Multiply the thousands, add any extra thousands. Finally→ Check for reasonableness! ✅