五年级数学速算题

Question

如题所述

Answer 1

56.7+98
=56.7+100-2
=156.7-2
=154.7
12.5×48×9
=（12.5×8）×（6×9）
=100×54
=5400
1/2×1/2×1/4×1/4
=1/4×1/4×1/4
=1/16×1/4
=1/64
79×17/78

=（78+1）×17/78
=78×17/78+17/78
=17+17/78
=17又17/78
3.2×87.5%÷1.6×8

=（3.2÷1.6）×（7/8×8）
=2×7
=14
4.8×101

=4.8×100+4.8
=480+4.8
=484.8
4.8×101-4.8
=4.8×（101-1）
=4.8×100
=480
0.875-1/4+1/8-1/4

=（0.875+1/8）-（1/4+1/4）
=1-1/2
=1/2
3.5÷1.4

=3.5÷0.7÷2
=5÷2
=2.5
0.875-3/4+1/8+1/4

=（0.875+1/8）-（3/4-1/4）
=1-1/2
=1/2