Adding three-digit numbers 100 to 400 (Horizontal Questions - Full Page)

This basic Addition worksheet is designed to help kids practice adding three-digit numbers (100 through 400) with addition questions that change each time you visit. This math worksheet is printable and displays a full page math sheet with Horizontal Addition questions.

With this math sheet generator, you can easily create Addition worksheets that are never the same and always different, providing you with an unlimited supply of math sheets to use in the classroom or at home.

Each math sheet also has an optional answer key checkbox that you can select, if you wish to print an answer key to go along with your math worksheet. And there are six different question styles to choose from, as listed below.

Possible Questions:

The possible addition questions on this math worksheet are:

  • 100+100, 101+100, 102+100, 103+100, 104+100, 105+100 ... 400+100
  • 100+101, 101+101, 102+101, 103+101, 104+101, 105+101 ... 400+101
  • 100+102, 101+102, 102+102, 103+102, 104+102, 105+102 ... 400+102
  • ...
  • 100+400, 101+400, 102+400, 103+400, 104+400, 105+400 ... 400+400
ANSWER KEY
204 + 282 =
 486
348 + 392 =
 740
326 + 192 =
 518
332 + 190 =
 522
335 + 174 =
 509
202 + 284 =
 486
285 + 226 =
 511
138 + 164 =
 302
246 + 275 =
 521
172 + 167 =
 339
283 + 322 =
 605
393 + 218 =
 611
365 + 180 =
 545
274 + 261 =
 535
137 + 257 =
 394
179 + 269 =
 448
154 + 322 =
 476
341 + 157 =
 498
100 + 175 =
 275
142 + 188 =
 330
340 + 229 =
 569
399 + 190 =
 589
159 + 394 =
 553
265 + 138 =
 403
107 + 145 =
 252
292 + 247 =
 539
260 + 375 =
 635
285 + 177 =
 462
387 + 381 =
 768
356 + 337 =
 693
170 + 159 =
 329
218 + 173 =
 391
154 + 270 =
 424
367 + 275 =
 642
181 + 260 =
 441
271 + 196 =
 467
216 + 189 =
 405
160 + 236 =
 396
137 + 389 =
 526
371 + 113 =
 484
256 + 228 =
 484
400 + 225 =
 625
261 + 159 =
 420
107 + 337 =
 444
296 + 316 =
 612
187 + 227 =
 414
127 + 130 =
 257
189 + 260 =
 449
220 + 326 =
 546
361 + 394 =
 755
255 + 329 =
 584
106 + 384 =
 490
124 + 230 =
 354
239 + 166 =
 405
165 + 332 =
 497
375 + 158 =
 533
268 + 133 =
 401
307 + 300 =
 607
181 + 245 =
 426
238 + 155 =
 393

 Check this box to display the answer key

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