3A · Chapter 5 · Practice
Practice B
Attempt independently, then review the full reasoning in the answer key.
Attempt independently, then review the full reasoning in the answer key. No name, account, or answer is transmitted to any server.
Assessment · 12 questions
Problems
The complete solutions are available here after each question and on the printable answer-key page.
- A1
Calculate 15 × 2 and show the exchanges.
Show answer and reasoning
Answer: 30
15×2 = 0 + 20 + 10 = 30; combine partial products and exchange groups of ten.
- A2
Calculate 25 × 2 and show the exchanges.
Show answer and reasoning
Answer: 50
25×2 = 0 + 40 + 10 = 50; combine partial products and exchange groups of ten.
- A3
Calculate 35 × 2 and show the exchanges.
Show answer and reasoning
Answer: 70
35×2 = 0 + 60 + 10 = 70; combine partial products and exchange groups of ten.
- A4
Calculate 55 × 3 and show the exchanges.
Show answer and reasoning
Answer: 165
55×3 = 0 + 150 + 15 = 165; combine partial products and exchange groups of ten.
- A5
Calculate 65 × 3 and show the exchanges.
Show answer and reasoning
Answer: 195
65×3 = 0 + 180 + 15 = 195; combine partial products and exchange groups of ten.
- A6
Calculate 75 × 3 and show the exchanges.
Show answer and reasoning
Answer: 225
75×3 = 0 + 210 + 15 = 225; combine partial products and exchange groups of ten.
- A7
Calculate 216 × 2 and show the exchanges.
Show answer and reasoning
Answer: 432
216×2 = 400 + 20 + 12 = 432; combine partial products and exchange groups of ten.
- A8
Calculate 316 × 2 and show the exchanges.
Show answer and reasoning
Answer: 632
316×2 = 600 + 20 + 12 = 632; combine partial products and exchange groups of ten.
- A9
Calculate 126 × 2 and show the exchanges.
Show answer and reasoning
Answer: 252
126×2 = 200 + 40 + 12 = 252; combine partial products and exchange groups of ten.
- A10
Calculate 157 × 3 and show the exchanges.
Show answer and reasoning
Answer: 471
157×3 = 300 + 150 + 21 = 471; combine partial products and exchange groups of ten.
- A11
Calculate 257 × 3 and show the exchanges.
Show answer and reasoning
Answer: 771
257×3 = 600 + 150 + 21 = 771; combine partial products and exchange groups of ten.
- A12
Calculate 357 × 3 and show the exchanges.
Show answer and reasoning
Answer: 1071
357×3 = 900 + 150 + 21 = 1071; combine partial products and exchange groups of ten.