Rounding Significant Figures - Free Printable

Here are the solutions for rounding each number to 2 significant figures (2 sf).

Step-by-step logic:
1. Identify the first two non-zero digits starting from the left. These are your "significant" digits.
2. Look at the digit immediately to the right of the second significant digit.
3. If that digit is 5 or greater, round the second significant digit up by one.
4. If that digit is less than 5, keep the second significant digit the same.
5. Replace any remaining whole number places with zeros to keep the value correct. Drop any decimal places after the second significant figure.

Calculations:

1) 172: First two digits are 1 and 7. Next is 2 (less than 5). Keep 17. Add 0 for place value. → 170
2) 714: First two digits are 7 and 1. Next is 4 (less than 5). Keep 71. Add 0. → 710
3) 456: First two digits are 4 and 5. Next is 6 (5 or more). Round 5 up to 6. Add 0. → 460
4) 3152: First two digits are 3 and 1. Next is 5 (5 or more). Round 1 up to 2. Add 0s. → 3200
5) 2037: First two digits are 2 and 0. Next is 3 (less than 5). Keep 20. Add 0s. → 2000
6) 8709: First two digits are 8 and 7. Next is 0 (less than 5). Keep 87. Add 0s. → 8700
7) 15.8: First two digits are 1 and 5. Next is 8 (5 or more). Round 5 up to 6. → 16
8) 37.27: First two digits are 3 and 7. Next is 2 (less than 5). Keep 37. → 37
9) 71.05: First two digits are 7 and 1. Next is 0 (less than 5). Keep 71. → 71
10) 5.683: First two digits are 5 and 6. Next is 8 (5 or more). Round 6 up to 7. → 5.7
11) 2.639: First two digits are 2 and 6. Next is 3 (less than 5). Keep 26. → 2.6
12) 8.448: First two digits are 8 and 4. Next is 4 (less than 5). Keep 84. → 8.4
13) 0.304: Skip the leading 0. First two sig figs are 3 and 0. Next is 4 (less than 5). Keep 30. → 0.30
14) 0.647: Skip leading 0. First two sig figs are 6 and 4. Next is 7 (5 or more). Round 4 up to 5. → 0.65
15) 0.853: Skip leading 0. First two sig figs are 8 and 5. Next is 3 (less than 5). Keep 85. → 0.85
16) 0.0328: Skip leading 0s. First two sig figs are 3 and 2. Next is 8 (5 or more). Round 2 up to 3. → 0.033
17) 0.0175: Skip leading 0s. First two sig figs are 1 and 7. Next is 5 (5 or more). Round 7 up to 8. → 0.018
18) 0.0652: Skip leading 0s. First two sig figs are 6 and 5. Next is 2 (less than 5). Keep 65. → 0.065
19) 3247: First two digits are 3 and 2. Next is 4 (less than 5). Keep 32. Add 0s. → 3200
20) 1.83: First two digits are 1 and 8. Next is 3 (less than 5). Keep 18. → 1.8
21) 266: First two digits are 2 and 6. Next is 6 (5 or more). Round 6 up to 7. Add 0. → 270
22) 62.34: First two digits are 6 and 2. Next is 3 (less than 5). Keep 62. → 62
23) 17.58: First two digits are 1 and 7. Next is 5 (5 or more). Round 7 up to 8. → 18
24) 2.729: First two digits are 2 and 7. Next is 2 (less than 5). Keep 27. → 2.7
25) 0.0625: Skip leading 0s. First two sig figs are 6 and 2. Next is 5 (5 or more). Round 2 up to 3. → 0.063
26) 75.08: First two digits are 7 and 5. Next is 0 (less than 5). Keep 75. → 75
27) 29.69: First two digits are 2 and 9. Next is 6 (5 or more). Round 9 up. This makes it 30. → 30
28) 1.834: First two digits are 1 and 8. Next is 3 (less than 5). Keep 18. → 1.8
29) 72835: First two digits are 7 and 2. Next is 8 (5 or more). Round 2 up to 3. Add 0s. → 73000
30) 0.0518: Skip leading 0s. First two sig figs are 5 and 1. Next is 8 (5 or more). Round 1 up to 2. → 0.052

Extra Numbers for the Boxes:
*(Note: There are many possible answers. Here are three examples for each that fit the rule.)*

* Rounds to 150: 148, 152, 149
* Rounds to 1500: 1490, 1510, 1540
* Rounds to 1.5: 1.46, 1.54, 1.49
* Rounds to 0.15: 0.146, 0.152, 0.149

──────────────────────────────────────

Final Answer:
1) 170
2) 710
3) 460
4) 3200
5) 2000
6) 8700
7) 16
8) 37
9) 71
10) 5.7
11) 2.6
12) 8.4
13) 0.30
14) 0.65
15) 0.85
16) 0.033
17) 0.018
18) 0.065
19) 3200
20) 1.8
21) 270
22) 62
23) 18
24) 2.7
25) 0.063
26) 75
27) 30
28) 1.8
29) 73000
30) 0.052