Rounding Significant Figures - Free Printable

Here are the solutions to the rounding problems on the sheet.

Part 1: Round these numbers to 1 significant figure

To round to 1 significant figure, look at the first non-zero digit. Then look at the digit immediately to its right. If that digit is 5 or more, round up. If it is less than 5, keep the first digit the same and turn the rest into zeros (or remove them if they are decimals).

Row 1:
* 3186: The first digit is 3. The next is 1 (less than 5). Keep 3, change rest to zeros. → 3000
* 92: First digit 9. Next is 2 (less than 5). → 90
* 2171: First digit 2. Next is 1 (less than 5). → 2000
* 3155: First digit 3. Next is 1 (less than 5). → 3000

Row 2:
* 41326: First digit 4. Next is 1 (less than 5). → 40000
* 91693: First digit 9. Next is 1 (less than 5). → 90000
* 61272: First digit 6. Next is 1 (less than 5). → 60000

Row 3:
* 711023: First digit 7. Next is 1 (less than 5). → 700000
* 818441: First digit 8. Next is 1 (less than 5). → 800000
* 916822: First digit 9. Next is 1 (less than 5). → 900000

Row 4:
* 1015.63: First digit 1. Next is 0 (less than 5). → 1000
* 1212.29: First digit 1. Next is 2 (less than 5). → 1000
* 1294.86: First digit 1. Next is 2 (less than 5). → 1000

Row 5:
* 1510.34: First digit 1. Next is 5 (5 or more). Round the 1 up to a 2. → 2000
* 1410.67: First digit 1. Next is 4 (less than 5). → 1000
* 1519.82: First digit 1. Next is 5 (5 or more). Round the 1 up to a 2. → 2000

Row 6:
* 1610.0324: First digit 1. Next is 6 (5 or more). Round up to 2. → 2000
* 1710.017: First digit 1. Next is 7 (5 or more). Round up to 2. → 2000
* 1810.0023: First digit 1. Next is 8 (5 or more). Round up to 2. → 2000

Row 7:
* 191327: First digit 1. Next is 9 (5 or more). Round up to 2. → 200000
* 2110.17: First digit 2. Next is 1 (less than 5). → 2000
* 2512027: First digit 2. Next is 5 (5 or more). Round up to 3. → 3000000

Row 8:
* 2216274: First digit 2. Next is 2 (less than 5). → 2000000
* 29127.8: First digit 2. Next is 9 (5 or more). Round up to 3. → 30000
* 241276: First digit 2. Next is 4 (less than 5). → 200000

Row 9:
* 2510.62: First digit 2. Next is 5 (5 or more). Round up to 3. → 3000
* 2917958: First digit 2. Next is 9 (5 or more). Round up to 3. → 3000000
* 27129.1: First digit 2. Next is 7 (5 or more). Round up to 3. → 30000

Row 10:
* 2811.83: First digit 2. Next is 8 (5 or more). Round up to 3. → 3000
* 2910.074: First digit 2. Next is 9 (5 or more). Round up to 3. → 3000
* 3017.063: First digit 3. Next is 0 (less than 5). → 3000

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Part 2: Write 3 more numbers in each box

You need to find numbers that would round to the target number when rounded to 1 significant figure.

Box 1: Rounds to 500
* *Rule:* The first digit must be 4 (rounding up) or 5 (staying same/rounding down).
* Examples: 450, 482, 521

Box 2: Rounds to 10
* *Rule:* The first digit must be roughly around 10. Usually 5 to 14.
* Examples: 6, 12, 14

Box 3: Rounds to 0.2
* *Rule:* Look at the decimal place. You want numbers close to 0.2.
* Examples: 0.16, 0.21, 0.24

Box 4: Rounds to 0.51
* *Note:* This box label says "Rounds to 0.51", but the column header says "Round to 1 sig fig". 0.51 has *two* significant figures. Assuming the instruction is strictly "1 significant figure", the target would be 0.5. If the target is actually 0.51 (2 sig figs), the logic is different. Given the header, I will assume the target is 0.5 (1 sig fig).
* *Correction based on typical worksheets:* Often these boxes ask for numbers that result in the specific value shown. If we treat 0.51 as the target for *2 sig figs*, examples are 0.505, 0.512, 0.514. However, sticking to the main rule of the sheet (1 sig fig), let's look at the box labeled 0.51. It is likely a typo for 0.5 or asking for 2 sig figs. Let's provide numbers that round to 0.5 (1 sig fig) to stay consistent with the rest of the sheet, OR numbers that round to 0.51 if we ignore the header.
* *Safest bet for 1 Sig Fig context:* The box likely meant 0.5.
* Examples for 0.5: 0.46, 0.52, 0.54
* *If strict to the text "0.51":*
* Examples: 0.506, 0.512, 0.514

*(Self-Correction for Final Answer)*: Looking closely at the last box, it says `0.51`. The previous ones are `500`, `10`, `0.2`. These are all 1 significant figure results. `0.51` is two. It is highly probable the question intends for you to write numbers that round to 0.5 (ignoring the '1' as a typo) OR it switched rules for the last box. I will provide numbers that round to 0.51 just in case, but note that for 1 sig fig, the answer would be different. Actually, looking at the pattern, `0.2` is 1 sig fig. `0.51` is definitely 2. I will provide numbers that round to 0.51 to be safe, as that is what is written.

Let's re-read the prompt carefully. "Write 3 more numbers in each box."
Box 1: Rounds to 500. (1 sig fig: 450-549 approx).
Box 2: Rounds to 10. (1 sig fig: 5-14 approx).
Box 3: Rounds to 0.2. (1 sig fig: 0.15-0.24 approx).
Box 4: Rounds to 0.51. (This breaks the pattern. I will provide numbers that round to 0.51 to 2 decimal places/sig figs).

Final Answer:

Part 1: Rounding Table

| | | | |
| :--- | :--- | :--- | :--- |
| 3000 | 90 | 2000 | 3000 |
| 40000 | 90000 | 60000 | |
| 700000 | 800000 | 900000 | |
| 1000 | 1000 | 1000 | |
| 2000 | 1000 | 2000 | |
| 2000 | 2000 | 2000 | |
| 200000 | 2000 | 3000000 | |
| 2000000 | 30000 | 200000 | |
| 3000 | 3000000 | 30000 | |
| 3000 | 3000 | 3000 | |

Part 2: Three Numbers for Each Box
*(Note: There are many correct answers. Here are three examples for each.)*

* Rounds to 500: 460, 510, 540
* Rounds to 10: 6, 12, 14
* Rounds to 0.2: 0.16, 0.21, 0.23
* Rounds to 0.51: 0.505, 0.512, 0.514