Multiplying Large Numbers: 3-Digit by 2-Digit
Practice using partial products and standard multiplication
Multiplying Large Numbers: 3-Digit by 2-Digit
Practice using partial products and standard multiplication
Math - Grade 4-5
- 1
Find the product: 234 × 12.
Break 12 into 10 + 2.
The product is 2,808 because 234 × 10 = 2,340 and 234 × 2 = 468, and 2,340 + 468 = 2,808. - 2
Find the product: 315 × 24.
The product is 7,560 because 315 × 20 = 6,300 and 315 × 4 = 1,260, and 6,300 + 1,260 = 7,560. - 3
Use partial products to solve: 428 × 36.
Multiply by 30 first, then multiply by 6.
The product is 15,408 because 428 × 30 = 12,840 and 428 × 6 = 2,568, and 12,840 + 2,568 = 15,408. - 4
Find the product: 507 × 18.
The product is 9,126 because 507 × 10 = 5,070 and 507 × 8 = 4,056, and 5,070 + 4,056 = 9,126. - 5
Find the product: 672 × 45.
Break 45 into 40 + 5.
The product is 30,240 because 672 × 40 = 26,880 and 672 × 5 = 3,360, and 26,880 + 3,360 = 30,240. - 6
Solve using the standard algorithm: 189 × 27.
The product is 5,103 because 189 × 20 = 3,780 and 189 × 7 = 1,323, and 3,780 + 1,323 = 5,103. - 7
Find the product: 746 × 32.
Remember that the 3 in 32 means 30, not 3.
The product is 23,872 because 746 × 30 = 22,380 and 746 × 2 = 1,492, and 22,380 + 1,492 = 23,872. - 8
Find the product: 903 × 16.
The product is 14,448 because 903 × 10 = 9,030 and 903 × 6 = 5,418, and 9,030 + 5,418 = 14,448. - 9
A school orders 128 boxes of pencils. Each box has 24 pencils. How many pencils does the school order in all?
Multiply 128 by 20 and by 4, then add the partial products.
The school orders 3,072 pencils in all because 128 × 24 = 3,072. - 10
A farmer plants 365 seeds in each row. There are 52 rows. How many seeds does the farmer plant in all?
The farmer plants 18,980 seeds in all because 365 × 52 = 18,980. - 11
Estimate first, then find the exact product: 489 × 61.
Use 500 × 60 for a quick estimate.
A reasonable estimate is 30,000 because 489 is close to 500 and 61 is close to 60. The exact product is 29,829 because 489 × 61 = 29,829. - 12
A student solved 236 × 14 by adding 236 × 4 and 236 × 1. The student got 1,180. Explain the mistake and find the correct product.
Think about the place value of each digit in 14.
The mistake is that the 1 in 14 means 10, not 1. The correct product is 3,304 because 236 × 10 = 2,360 and 236 × 4 = 944, and 2,360 + 944 = 3,304. - 13
Use an area model to solve: 718 × 23.
The product is 16,514 because 718 × 20 = 14,360 and 718 × 3 = 2,154, and 14,360 + 2,154 = 16,514. - 14
Find 254 × 39. Use 254 × 40 to help if you want.
Since 39 is one less than 40, multiply by 40 and subtract one group of 254.
The product is 9,906 because 254 × 40 = 10,160 and one group of 254 must be subtracted, so 10,160 - 254 = 9,906. - 15
A theater has 156 seats in each section. There are 28 sections. How many seats are in the theater?
Break 28 into 20 + 8.
There are 4,368 seats in the theater because 156 × 28 = 4,368.