48×213-13
=（50-2）x213-13
=50x213-2x213-13
=10650-426-13
=10211
48×213-13
=48x200+48x13-13
=9600+47x13
=9600+（50-3）x13
=9600+50x13-3x13
=9600+650-39
=10211