Estimating Fractions Worksheets - 15 Worksheets Library - Free Printable

To solve this worksheet, we need to estimate each fraction as either 0 or 1, and then add those estimates together.

How to Estimate:

- If the numerator is much smaller than the denominator (like 1/5, 2/9, 3/8), the fraction is close to 0.
- If the numerator is close to the denominator (like 4/5, 7/8, 16/17), the fraction is close to 1.
- A good rule of thumb: if the numerator is less than half the denominator → estimate 0.
If the numerator is half or more → estimate 1.

Let’s go through each problem one by one.

---

1) 4/5 + 1/7
→ 4/5 ≈ 1 (since 4 is almost 5)
→ 1/7 ≈ 0 (since 1 is much less than 7)
→ Sum = 1 + 0 = 1

2) 3/7 + 2/4
→ 3/7 ≈ 0? Wait — 3 is less than half of 7? Half of 7 is 3.5 → so 3 < 3.5 → ≈ 0
→ 2/4 = 1/2 → exactly half → we’ll count it as 1 (since “half or more” = 1)
→ Sum = 0 + 1 = 1

*(Note: Some teachers may say 1/2 rounds to 0 or 1 — but in most elementary estimation for sums like this, 1/2 is rounded up to 1. We’ll follow that convention here.)*

3) 5/6 + 3/4
→ 5/6 ≈ 1
→ 3/4 ≈ 1
→ Sum = 1 + 1 = 2

4) 3/8 + 4/5
→ 3/8: half of 8 is 4 → 3 < 4 → ≈ 0
→ 4/5 ≈ 1
→ Sum = 0 + 1 = 1

5) 2/9 + 7/8
→ 2/9 ≈ 0
→ 7/8 ≈ 1
→ Sum = 0 + 1 = 1

6) 5/10 + 2/4
→ 5/10 = 1/2 → ≈ 1
→ 2/4 = 1/2 → ≈ 1
→ Sum = 1 + 1 = 2

7) 5/6 + 3/6
→ 5/6 ≈ 1
→ 3/6 = 1/2 → ≈ 1
→ Sum = 1 + 1 = 2

8) 4/8 + 5/6
→ 4/8 = 1/2 → ≈ 1
→ 5/6 ≈ 1
→ Sum = 1 + 1 = 2

9) 2/5 + 2/3
→ 2/5: half of 5 is 2.5 → 2 < 2.5 → ≈ 0
→ 2/3: half of 3 is 1.5 → 2 > 1.5 → ≈ 1
→ Sum = 0 + 1 = 1

10) 4/6 + 2/6
→ 4/6: half of 6 is 3 → 4 > 3 → ≈ 1
→ 2/6: 2 < 3 → ≈ 0
→ Sum = 1 + 0 = 1

11) 11/12 + 1/8
→ 11/12 ≈ 1
→ 1/8 ≈ 0
→ Sum = 1 + 0 = 1

12) 3/6 + 5/6
→ 3/6 = 1/2 → ≈ 1
→ 5/6 ≈ 1
→ Sum = 1 + 1 = 2

13) 2/3 + 7/9
→ 2/3 ≈ 1 (since 2 > 1.5)
→ 7/9: half of 9 is 4.5 → 7 > 4.5 → ≈ 1
→ Sum = 1 + 1 = 2

14) 1/7 + 2/6
→ 1/7 ≈ 0
→ 2/6 = 1/3 → half of 6 is 3 → 2 < 3 → ≈ 0
→ Sum = 0 + 0 = 0

15) 16/17 + 1/2
→ 16/17 ≈ 1
→ 1/2 → ≈ 1
→ Sum = 1 + 1 = 2

16) 4/5 + 1/2
→ 4/5 ≈ 1
→ 1/2 → ≈ 1
→ Sum = 1 + 1 = 2

17) 5/11 + 3/6
→ 5/11: half of 11 is 5.5 → 5 < 5.5 → ≈ 0
→ 3/6 = 1/2 → ≈ 1
→ Sum = 0 + 1 = 1

18) 4/5 + 2/3
→ 4/5 ≈ 1
→ 2/3 ≈ 1
→ Sum = 1 + 1 = 2

19) 5/6 + 3/6
→ 5/6 ≈ 1
→ 3/6 = 1/2 → ≈ 1
→ Sum = 1 + 1 = 2

20) 6/7 + 1/2
→ 6/7 ≈ 1
→ 1/2 → ≈ 1
→ Sum = 1 + 1 = 2

---

Now let’s list all the estimated sums:

1) 1
2) 1
3) 2
4) 1
5) 1
6) 2
7) 2
8) 2
9) 1
10) 1
11) 1
12) 2
13) 2
14) 0
15) 2
16) 2
17) 1
18) 2
19) 2
20) 2

Now add them all up:

Let’s group them:

- Zeros: only #14 → 0
- Ones: #1,2,4,5,9,10,11,17 → that’s 8 ones → 8
- Twos: #3,6,7,8,12,13,15,16,18,19,20 → that’s 11 twos → 22

Total = 0 + 8 + 22 = 30

Wait — let me double-check the count:

List again with numbers:

1:1 → total=1
2:1 → total=2
3:2 → total=4
4:1 → total=5
5:1 → total=6
6:2 → total=8
7:2 → total=10
8:2 → total=12
9:1 → total=13
10:1 → total=14
11:1 → total=15
12:2 → total=17
13:2 → total=19
14:0 → total=19
15:2 → total=21
16:2 → total=23
17:1 → total=24
18:2 → total=26
19:2 → total=28
20:2 → total=30 ✔

Yes, total sum of estimates is 30.

Final Answer:
30