1) \( 488 + 128 = 616 \)
\( 238 + 397 = 635 \)
\( 539 - 287 = 252 \)
\( 642 - 356 = 286 \)
2) \( 108 \times 2 = 216 \)
\( 214 \times 4 = 856 \)
\( 348 \times 2 = 696 \)
\( 115 \times 8 = 920 \)