Problems Involving Adding and Subtracting within 1000: Problems with Solutions

Solution:
400 + 300 = 700

Solution:
800 - 600 = 200

Solution:
120 + 230 = 350

Solution:
470 - 130 = 340

Solution:
620 - 410 = 210

Solution:
354 + 235 = 589

Solution:
746 - 521 = 225

Solution:
423 + 256 - 554 = ( 423 + 256) - 554 = 679 - 554 = 125

Solution:
964 - 513 - 251 = ( 964 - 513) - 251 = 451 - 251 = 200

Solution:
480 - (138 + 160)= 480 - 298 = 182

Solution:
200 + 40 + 200 + 40 = 240 + 240 = 480cm

Solution:
(683 - 571) + (829 - 315) = 112 + 514 = 626

Solution:
274 + [459 - (324 + 123)] = 274 + (459 - 447) = 274 + 12 = 286

Solution:
759 - 325 - 113 = 434 - 113 = 321
759 - (325 + 113) =759 - 438 = 321
Then they're equal.

Solution:
347 -125 + 232 - 121 = 222 + 111 = 333
347 +232) - ( 125 + 121) = 579 - 246 = 333
Then they're equal
We notice that we can add the numbers with plus between them, then the numbers with minus between them, and then we can do subtraction.

Solution:
From the quantity sold in the two days we subtract the quantity sold in the first day.
579 - 265 = 314

Solution:
143 + 132 + 120 = 275 + 120 = 395

Solution:
678 -(132 + 135) = 678 - 267 = 411 dollars

Solution:
385 + 104 = 489

Solution:
769 - 435 = 334

Solution:
359 - 233 = 126

Solution:
458 - 142 = $316

Solution:
472 + 517 = 989