Let’s solve each problem step by step. The main idea is to
round each number to its leading digit (the first non-zero digit), then multiply the rounded numbers to get an estimate.
---
Part 1: Round to the leading digit. Estimate the product.
We’ll do each one:
#### Left Column:
1.
1,908 × 8
→ Round 1,908 to leading digit:
2,000
→ 2,000 × 8 =
16,000
2.
7 × 1,108
→ Round 1,108 to leading digit:
1,000
→ 7 × 1,000 =
7,000
3.
81 × 32
→ Round 81 →
80, round 32 →
30
→ 80 × 30 =
2,400
4.
39 × 44
→ Round 39 →
40, round 44 →
40
→ 40 × 40 =
1,600
#### Right Column:
5.
5 × 6,099
→ Round 6,099 →
6,000
→ 5 × 6,000 =
30,000
6.
5,239 × 9
→ Round 5,239 →
5,000
→ 5,000 × 9 =
45,000
7.
19 × 62
→ Round 19 →
20, round 62 →
60
→ 20 × 60 =
1,200
8.
94 × 12
→ Round 94 →
90, round 12 →
10
→ 90 × 10 =
900
---
Part 2: Estimate the product. (Same rule — round to leading digit)
We’ll go row by row, left to right.
#### Row 1:
-
6 × 7,243 → 6 × 7,000 =
42,000
-
4,785 × 4 → 5,000 × 4 =
20,000
-
3 × 8,924 → 3 × 9,000 =
27,000
#### Row 2:
-
2,785 × 5 → 3,000 × 5 =
15,000
-
6,298 × 4 → 6,000 × 4 =
24,000
-
7 × 7,105 → 7 × 7,000 =
49,000
#### Row 3:
-
8 × 2,870 → 8 × 3,000 =
24,000
-
4,176 × 7 → 4,000 × 7 =
28,000
-
5 × 4,803 → 5 × 5,000 =
25,000
#### Row 4:
-
6,777 × 9 → 7,000 × 9 =
63,000
-
6 × 8,022 → 6 × 8,000 =
48,000
-
3,785 × 4 → 4,000 × 4 =
16,000
#### Row 5:
-
42 × 51 → 40 × 50 =
2,000
-
54 × 28 → 50 × 30 =
1,500
-
23 × 75 → 20 × 80 =
1,600
#### Row 6:
-
16 × 32 → 20 × 30 =
600
-
47 × 54 → 50 × 50 =
2,500
-
59 × 52 → 60 × 50 =
3,000
#### Row 7:
-
17 × 74 → 20 × 70 =
1,400
-
33 × 22 → 30 × 20 =
600
-
81 × 18 → 80 × 20 =
1,600
#### Row 8:
-
31 × 91 → 30 × 90 =
2,700
-
38 × 87 → 40 × 90 =
3,600
-
46 × 77 → 50 × 80 =
4,000
---
Final Answer:
Part 1:
- 1,908 × 8 ≈
16,000
- 7 × 1,108 ≈
7,000
- 81 × 32 ≈
2,400
- 39 × 44 ≈
1,600
- 5 × 6,099 ≈
30,000
- 5,239 × 9 ≈
45,000
- 19 × 62 ≈
1,200
- 94 × 12 ≈
900
Part 2:
Row 1:
42,000,
20,000,
27,000
Row 2:
15,000,
24,000,
49,000
Row 3:
24,000,
28,000,
25,000
Row 4:
63,000,
48,000,
16,000
Row 5:
2,000,
1,500,
1,600
Row 6:
600,
2,500,
3,000
Row 7:
1,400,
600,
1,600
Row 8:
2,700,
3,600,
4,000
Parent Tip: Review the logic above to help your child master the concept of estimation worksheets.
