Adding and Subtracting Within 1,000: Grade 2 Math Worksheet Answer Key – PDF Download

Grade 2 Add Worksheet Answer Key: problems 1–5

Problem 1: Add hundreds

Add the hundreds. The other digits stay the same.

1. \(200 + 500 = 700\). \(700\)
2. \(340 + 200 = 540\). \(540\)
3. \(125 + 300 = 425\). \(425\)
4. \(410 + 400 = 810\). \(810\)

Problem 2: Blocks without regrouping

Hundreds: \(2 + 1 = 3\). Tens: \(1 + 2 = 3\). Ones: \(3 + 4 = 7\). 3 hundreds, 3 tens and 7 ones is 337. \(213 + 124 = 337\)

Problem 3: Add with no carrying

1. Ones: \(2 + 6 = 8\). Tens: \(4 + 5 = 9\). Hundreds: \(3 + 1 = 4\). \(342 + 156 = 498\)
2. Ones: \(1 + 7 = 8\). Tens: \(2 + 6 = 8\). Hundreds: \(5 + 2 = 7\). \(521 + 267 = 788\)
3. Ones: \(5 + 3 = 8\). Tens: \(3 + 6 = 9\). Hundreds: \(6 + 1 = 7\). \(635 + 163 = 798\)
4. Ones: \(4 + 5 = 9\). Tens: \(0 + 8 = 8\). Hundreds: \(7 + 1 = 8\). \(704 + 185 = 889\)

Problem 4: Carry the ones

Ones: \(7 + 5 = 12\). Trade 10 ones for 1 ten, so 2 ones are left. Tens: \(4 + 3 + 1 = 8\). Hundreds: \(2 + 1 = 3\).

\(247 + 135 = 382\)

Problem 5: Carry the tens

1. Ones: \(1 + 0 = 1\). Tens: \(8 + 5 = 13\). That is 1 hundred and \(3\) tens. Write \(3\), carry 1. Hundreds: \(2 + 1 + 1 = 4\). \(281 + 150 = 431\)
2. Ones: \(5 + 0 = 5\). Tens: \(6 + 8 = 14\). That is 1 hundred and \(4\) tens. Write \(4\), carry 1. Hundreds: \(3 + 2 + 1 = 6\). \(365 + 280 = 645\)
3. Ones: \(2 + 0 = 2\). Tens: \(7 + 6 = 13\). That is 1 hundred and \(3\) tens. Write \(3\), carry 1. Hundreds: \(4 + 3 + 1 = 8\). \(472 + 360 = 832\)
4. Ones: \(4 + 0 = 4\). Tens: \(5 + 7 = 12\). That is 1 hundred and \(2\) tens. Write \(2\), carry 1. Hundreds: \(1 + 2 + 1 = 4\). \(154 + 270 = 424\)

Grade 2 Add Worksheet Answer Key: problems 6–10

Problem 6: Carry twice

1. Ones: \(8 + 7 = 15\). That is 1 ten and \(5\) ones. Write \(5\), carry 1. Tens: \(5 + 6 + 1 = 12\). That is 1 hundred and \(2\) tens. Write \(2\), carry 1. Hundreds: \(3 + 1 + 1 = 5\). \(358 + 167 = 525\)
2. Ones: \(9 + 6 = 15\). That is 1 ten and \(5\) ones. Write \(5\), carry 1. Tens: \(7 + 4 + 1 = 12\). That is 1 hundred and \(2\) tens. Write \(2\), carry 1. Hundreds: \(4 + 2 + 1 = 7\). \(479 + 246 = 725\)
3. Ones: \(5 + 9 = 14\). That is 1 ten and \(4\) ones. Write \(4\), carry 1. Tens: \(8 + 4 + 1 = 13\). That is 1 hundred and \(3\) tens. Write \(3\), carry 1. Hundreds: \(2 + 3 + 1 = 6\). \(285 + 349 = 634\)
4. Ones: \(7 + 8 = 15\). That is 1 ten and \(5\) ones. Write \(5\), carry 1. Tens: \(6 + 3 + 1 = 10\). That is 1 hundred and \(0\) tens. Write \(0\), carry 1. Hundreds: \(5 + 2 + 1 = 8\). \(567 + 238 = 805\)

Problem 7: Subtract hundreds

Subtract the hundreds. The other digits stay the same.

1. \(900 – 400 = 500\). \(500\)
2. \(780 – 300 = 480\). \(480\)
3. \(650 – 200 = 450\). \(450\)
4. \(845 – 500 = 345\). \(345\)

Problem 8: Subtract with no trading

1. Ones: \(7 – 3 = 4\). Tens: \(8 – 5 = 3\). Hundreds: \(4 – 2 = 2\). \(487 – 253 = 234\)
2. Ones: \(5 – 2 = 3\). Tens: \(6 – 4 = 2\). Hundreds: \(7 – 3 = 4\). \(765 – 342 = 423\)
3. Ones: \(8 – 4 = 4\). Tens: \(9 – 6 = 3\). Hundreds: \(5 – 2 = 3\). \(598 – 264 = 334\)
4. Ones: \(9 – 5 = 4\). Tens: \(4 – 1 = 3\). Hundreds: \(8 – 7 = 1\). \(849 – 715 = 134\)

Problem 9: Trade a ten for ones

Ones: \(5\) is less than \(8\), so trade 1 ten for 10 ones. Now there are \(15\) ones and \(5\) tens. Ones: \(15 – 8 = 7\). Tens: \(5 – 4 = 1\). Hundreds: \(3 – 1 = 2\). \(365 – 148 = 217\)

Problem 10: Trade a hundred for tens

1. Ones: \(4 – 0 = 4\). Tens: \(2\) is less than \(7\), so trade 1 hundred for 10 tens. Now there are \(12\) tens and \(4\) hundreds. Tens: \(12 – 7 = 5\). Hundreds: \(4 – 3 = 1\). \(524 – 370 = 154\)
2. Ones: \(8 – 0 = 8\). Tens: \(1\) is less than \(5\), so trade 1 hundred for 10 tens. Now there are \(11\) tens and \(5\) hundreds. Tens: \(11 – 5 = 6\). Hundreds: \(5 – 2 = 3\). \(618 – 250 = 368\)
3. Ones: \(3 – 0 = 3\). Tens: \(4\) is less than \(8\), so trade 1 hundred for 10 tens. Now there are \(14\) tens and \(6\) hundreds. Tens: \(14 – 8 = 6\). Hundreds: \(6 – 3 = 3\). \(743 – 380 = 363\)
4. Ones: \(5 – 0 = 5\). Tens: \(3\) is less than \(6\), so trade 1 hundred for 10 tens. Now there are \(13\) tens and \(7\) hundreds. Tens: \(13 – 6 = 7\). Hundreds: \(7 – 4 = 3\). \(835 – 460 = 375\)

Grade 2 Add Worksheet Answer Key: problems 11–15

Problem 11: Trade twice

1. Ones: \(1\) is less than \(6\), so trade 1 ten for 10 ones. Now there are \(11\) ones and \(2\) tens. Ones: \(11 – 6 = 5\). Tens: \(2\) is less than \(8\), so trade 1 hundred for 10 tens. Now there are \(12\) tens and \(3\) hundreds. Tens: \(12 – 8 = 4\). Hundreds: \(3 – 2 = 1\). \(431 – 286 = 145\)
2. Ones: \(4\) is less than \(8\), so trade 1 ten for 10 ones. Now there are \(14\) ones and \(1\) tens. Ones: \(14 – 8 = 6\). Tens: \(1\) is less than \(5\), so trade 1 hundred for 10 tens. Now there are \(11\) tens and \(6\) hundreds. Tens: \(11 – 5 = 6\). Hundreds: \(6 – 3 = 3\). \(724 – 358 = 366\)
3. Ones: \(3\) is less than \(8\), so trade 1 ten for 10 ones. Now there are \(13\) ones and \(5\) tens. Ones: \(13 – 8 = 5\). Tens: \(5\) is less than \(7\), so trade 1 hundred for 10 tens. Now there are \(15\) tens and \(4\) hundreds. Tens: \(15 – 7 = 8\). Hundreds: \(4 – 2 = 2\). \(563 – 278 = 285\)
4. Ones: \(5\) is less than \(7\), so trade 1 ten for 10 ones. Now there are \(15\) ones and \(0\) tens. Ones: \(15 – 7 = 8\). Tens: \(0\) is less than \(6\), so trade 1 hundred for 10 tens. Now there are \(10\) tens and \(7\) hundreds. Tens: \(10 – 6 = 4\). Hundreds: \(7 – 4 = 3\). \(815 – 467 = 348\)

Problem 12: Zero in the tens place

1. Ones: \(0\) is less than \(3\) and there are 0 tens. Trade 1 hundred for 10 tens, then trade 1 ten for 10 ones. Now there are \(3\) hundreds, \(9\) tens and \(10\) ones. Ones: \(10 – 3 = 7\). Tens: \(9 – 5 = 4\). Hundreds: \(3 – 1 = 2\). \(400 – 153 = 247\)
2. Ones: \(0\) is less than \(8\) and there are 0 tens. Trade 1 hundred for 10 tens, then trade 1 ten for 10 ones. Now there are \(6\) hundreds, \(9\) tens and \(10\) ones. Ones: \(10 – 8 = 2\). Tens: \(9 – 6 = 3\). Hundreds: \(6 – 2 = 4\). \(700 – 268 = 432\)

Problem 13: Add 10 or 100 in your head

1. \(345 + 10 = 355\): the tens digit goes up by 1. \(355\)
2. \(345 + 100 = 445\): the hundreds digit goes up by 1. \(445\)
3. \(678 + 10 = 688\): the tens digit goes up by 1. \(688\)
4. \(520 + 100 = 620\): the hundreds digit goes up by 1. \(620\)

Problem 14: Subtract 10 or 100 in your head

1. \(482 – 10 = 472\): the tens digit goes down by 1. \(472\)
2. \(482 – 100 = 382\): the hundreds digit goes down by 1. \(382\)
3. \(760 – 10 = 750\): the tens digit goes down by 1. \(750\)
4. \(905 – 100 = 805\): the hundreds digit goes down by 1. \(805\)

Problem 15: Crossing a hundred

1. 29 tens plus 1 ten is 30 tens, which is 300. \(300\)
2. 89 tens plus 1 ten is 90 tens, which is 900. \(900\)
3. 60 tens minus 1 ten is 59 tens, which is 590. \(590\)
4. 50 tens minus 1 ten is 49 tens, which is 490. \(490\)

Grade 2 Add Worksheet Answer Key: problems 16–20

Problem 16: Missing number

1. Subtract to find the missing part. Ones: \(2\) is less than \(5\), so trade 1 ten for 10 ones. Now there are \(12\) ones and \(0\) tens. Ones: \(12 – 5 = 7\). Tens: \(0\) is less than \(3\), so trade 1 hundred for 10 tens. Now there are \(10\) tens and \(5\) hundreds. Tens: \(10 – 3 = 7\). Hundreds: \(5 – 2 = 3\). \(612 – 235 = 377\) \(377\)
2. The missing number is the difference. Ones: \(4\) is less than \(9\) and there are 0 tens. Trade 1 hundred for 10 tens, then trade 1 ten for 10 ones. Now there are \(7\) hundreds, \(9\) tens and \(14\) ones. Ones: \(14 – 9 = 5\). Tens: \(9 – 5 = 4\). Hundreds: \(7 – 4 = 3\). \(804 – 459 = 345\) \(345\)

Problem 17: Check by adding

Ones: \(3\) is less than \(8\), so trade 1 ten for 10 ones. Now there are \(13\) ones and \(5\) tens. Ones: \(13 – 8 = 5\). Tens: \(5\) is less than \(7\), so trade 1 hundred for 10 tens. Now there are \(15\) tens and \(4\) hundreds. Tens: \(15 – 7 = 8\). Hundreds: \(4 – 2 = 2\). \(563 – 278 = 285\)

Check: Ones: \(5 + 8 = 13\). That is 1 ten and \(3\) ones. Write \(3\), carry 1. Tens: \(8 + 7 + 1 = 16\). That is 1 hundred and \(6\) tens. Write \(6\), carry 1. Hundreds: \(2 + 2 + 1 = 5\). \(285 + 278 = 563\)

Problem 18: Find the mistake

Jamal wrote the 5 and the 1 but forgot to carry. The 15 ones should give 1 ten, and the 11 tens should give 1 hundred.

Ones: \(7 + 8 = 15\). That is 1 ten and \(5\) ones. Write \(5\), carry 1. Tens: \(6 + 5 + 1 = 12\). That is 1 hundred and \(2\) tens. Write \(2\), carry 1. Hundreds: \(2 + 1 + 1 = 4\). \(267 + 158 = 425\)

Check: \(425 – 158 = 267\).

Problem 19: Farmers market apples

Ones: \(8 + 5 = 13\). That is 1 ten and \(3\) ones. Write \(3\), carry 1. Tens: \(4 + 7 + 1 = 12\). That is 1 hundred and \(2\) tens. Write \(2\), carry 1. Hundreds: \(2 + 1 + 1 = 4\). \(248 + 175 = 423\)

Check: \(423 – 175 = 248\). Diego sells 423 apples.

Problem 20: Library books

Ones: \(2\) is less than \(7\), so trade 1 ten for 10 ones. Now there are \(12\) ones and \(0\) tens. Ones: \(12 – 7 = 5\). Tens: \(0\) is less than \(8\), so trade 1 hundred for 10 tens. Now there are \(10\) tens and \(4\) hundreds. Tens: \(10 – 8 = 2\). Hundreds: \(4 – 1 = 3\). \(512 – 187 = 325\)

Check: \(325 + 187 = 512\). 325 books are left.

Grade 2 Add Worksheet Answer Key: problems 21–24

Problem 21: Road trip miles

1. Ones: \(8 + 6 = 14\). That is 1 ten and \(4\) ones. Write \(4\), carry 1. Tens: \(5 + 7 + 1 = 13\). That is 1 hundred and \(3\) tens. Write \(3\), carry 1. Hundreds: \(3 + 2 + 1 = 6\). \(358 + 276 = 634\)
2. Ones: \(8 – 6 = 2\). Tens: \(5\) is less than \(7\), so trade 1 hundred for 10 tens. Now there are \(15\) tens and \(2\) hundreds. Tens: \(15 – 7 = 8\). Hundreds: \(2 – 2 = 0\). \(358 – 276 = 82\)

Check: \(82 + 276 = 358\). 634 miles in all, and 82 more miles on Day 1.

Problem 22: Sticker collection

Step 1: Ones: \(5 + 0 = 5\). Tens: \(2 + 5 = 7\). Hundreds: \(3 + 1 = 4\). \(325 + 150 = 475\)

Step 2: Ones: \(5 – 5 = 0\). Tens: \(7 – 7 = 0\). Hundreds: \(4 – 2 = 2\). \(475 – 275 = 200\)

Priya has \(200\) stickers.

Problem 23: Theater seats

The empty seats start at 740. After 100 seats are taken: \(740 – 100 = 640\). After 10 more people sit: \(640 – 10 = 630\).

\(630\) seats are empty.

Problem 24: Bake sale cookies

Step 1: Ones: \(6 + 9 = 15\). That is 1 ten and \(5\) ones. Write \(5\), carry 1. Tens: \(5 + 8 + 1 = 14\). That is 1 hundred and \(4\) tens. Write \(4\), carry 1. Hundreds: \(2 + 1 + 1 = 4\). \(256 + 189 = 445\)

Step 2: \(445 – 300 = 145\). Subtract 3 hundreds.

Check: \(145 + 300 = 445\). \(145\) cookies are left.

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