Testinar Grade 5 math

Prime and Composite Numbers

Students will use factor reasoning to identify prime and composite numbers.

CH01-06 Decimal Place Value

Directions Solve each problem. Show your reasoning on the page or on separate paper. Check the answer key only after finishing.

What is \(45 \times 7\)?
1. 305
2. 315
3. 325
4. 350
What is \(24 \times 15\)?
1. 260
2. 320
3. 360
4. 460
A school orders 132 boxes of pencils. Each box has 24 pencils. How many pencils are ordered in all?
1. 2,968
2. 31,680
3. 3,248
4. 3,168
Estimate the product of \(23 \times 18\) by rounding each factor to the nearest ten, then multiply.
1. 360
2. 380
3. 420
4. 400
This area model shows \(25 \times 13\) broken into four partial products. What is the total product?
1. 315
2. 325
3. 335
4. 345
A school bought 12 boxes of colored pencils. Each box contains 24 pencils. How many pencils did the school buy?
1. 276
2. 288
3. 300
4. 312
What is \(31 \times 7\)?
1. 210
2. 231
3. 224
4. 217
A theater has 4 sections with 112 seats in each section. Which place-value sum can be used to find the total number of seats?
1. \(400+40+8\)
2. \(400+10+8\)
3. \(100+40+8\)
4. \(400+40+2\)

Teacher and parent reference

Answer key and explanations

B. 315
Break 45 into 40 and 5: \((40 \times 7) + (5 \times 7) = 280 + 35 = 315\).
C. 360
Multiply: \(24 \times 15 = 24 \times (10+5) = 240 + 120 = 360\).
D. 3,168
Multiply: \(132 \times 24 = 132 \times (20+4) = 2{,}640 + 528 = 3{,}168\).
D. 400
Round 23 to 20 and 18 to 20. Then \(20 \times 20 = 400\).
B. 325
Add the four partial products: \((20 \times 10) + (5 \times 10) + (20 \times 3) + (5 \times 3) = 200 + 50 + 60 + 15 = 325\).
B. 288
Multiply: \(12 \times 24 = 12 \times (20 + 4) = (12 \times 20) + (12 \times 4) = 240 + 48 = 288\) pencils.
D. 217
Multiply: \(31 \times 7 = (30 \times 7) + (1 \times 7) = 210 + 7 = 217\).
A. \(400+40+8\)
Use place value: \(112 \times 4 = (100 \times 4) + (10 \times 4) + (2 \times 4) = 400 + 40 + 8 = 448\) seats.