《2025年直播新课堂五年级数学上册人教版》

一、用简便方法计算。
8.88×12.5 6.59×34.5+65.5×6.59
0.5×4.9×4 4.5×3.6+6.4×4.5
26.3×99+26.3 1.25×32×0.25
6.57×101 3.65×1.9+0.365
0.125×9.62×80−96.2

答案： 8.88×12.5
=(8+0.8+0.08)×12.5
=8×12.5+0.8×12.5+0.08×12.5
=100+10+1
=111
6.59×34.5+65.5×6.59
=6.59×(34.5+65.5)
=6.59×100
=659
0.5×4.9×4
=0.5×4×4.9
=2×4.9
=9.8
4.5×3.6+6.4×4.5
=4.5×(3.6+6.4)
=4.5×10
=45
26.3×99+26.3
=26.3×(99+1)
=26.3×100
=2630
1.25×32×0.25
=1.25×8×4×0.25
=(1.25×8)×(4×0.25)
=10×1
=10
6.57×101
=6.57×(100+1)
=6.57×100+6.57×1
=657+6.57
=663.57
3.65×1.9+0.365
=3.65×1.9+3.65×0.1
=3.65×(1.9+0.1)
=3.65×2
=7.3
0.125×9.62×80−96.2
=0.125×80×9.62−96.2
=10×9.62−96.2
=96.2−96.2
=0

二、用简便方法计算。
2.65×1.7+13.5×0.17
19.98×37−199.8×1.9+1.998×20
19.94+99.7×99.8
66.6×9+22.2×33
5.5×7.7+33×0.55−5.5
3.8×0.45+0.38×4.2+0.038×13
752×1.25+4.45×12.5+0.035×125
(1+0.12+0.23+0.34)×(0.12+0.23)−(0.12+0.23)×(0.12+0.23+0.34)

答案： 2.65×1.7+13.5×0.17
=2.65×1.7+1.35×1.7
=(2.65+1.35)×1.7
=4×1.7
=6.8
19.98×37−199.8×1.9+1.998×20
=19.98×37−19.98×19+19.98×2
=19.98×(37−19+2)
=19.98×20
=399.6
19.94+99.7×99.8
=19.94+99.7×(100−0.2)
=19.94+9970−19.94
=9970
66.6×9+22.2×33
=66.6×9+22.2×3×11
=66.6×9+66.6×11
=66.6×(9+11)
=66.6×20
=1332
5.5×7.7+33×0.55−5.5
=5.5×7.7+3.3×5.5−5.5×1
=5.5×(7.7+3.3−1)
=5.5×10
=55
3.8×0.45+0.38×4.2+0.038×13
=3.8×0.45+3.8×0.42+3.8×0.13
=3.8×(0.45+0.42+0.13)
=3.8×1
=3.8
752×1.25+4.45×12.5+0.035×125
=752×1.25+44.5×1.25+3.5×1.25
=(752+44.5+3.5)×1.25
=800×1.25
=1000
(1+0.12+0.23+0.34)×(0.12+0.23)−(0.12+0.23)×(0.12+0.23+0.34)
=(0.12+0.23)×[(1+0.12+0.23+0.34)−(0.12+0.23+0.34)]
=(0.12+0.23)×1
=0.35