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
198 + 133 =
 331
393 + 372 =
 765
131 + 262 =
 393
350 + 195 =
 545
121 + 393 =
 514
140 + 335 =
 475
271 + 250 =
 521
244 + 282 =
 526
239 + 133 =
 372
367 + 386 =
 753
355 + 125 =
 480
275 + 283 =
 558
394 + 203 =
 597
253 + 178 =
 431
346 + 373 =
 719
154 + 282 =
 436
186 + 213 =
 399
381 + 361 =
 742
334 + 278 =
 612
214 + 353 =
 567
193 + 149 =
 342
161 + 267 =
 428
331 + 106 =
 437
345 + 143 =
 488
323 + 183 =
 506
230 + 147 =
 377
258 + 293 =
 551
180 + 339 =
 519
189 + 269 =
 458
212 + 228 =
 440
355 + 109 =
 464
149 + 117 =
 266
377 + 129 =
 506
227 + 134 =
 361
150 + 327 =
 477
159 + 239 =
 398
123 + 215 =
 338
315 + 308 =
 623
175 + 127 =
 302
187 + 272 =
 459
391 + 360 =
 751
158 + 330 =
 488
117 + 223 =
 340
252 + 257 =
 509
310 + 244 =
 554
257 + 258 =
 515
292 + 251 =
 543
150 + 105 =
 255
181 + 173 =
 354
143 + 192 =
 335
237 + 283 =
 520
179 + 356 =
 535
267 + 309 =
 576
391 + 221 =
 612
391 + 284 =
 675
130 + 353 =
 483
108 + 145 =
 253
387 + 247 =
 634
279 + 290 =
 569
221 + 262 =
 483

 Check this box to display the answer key

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