Simple calculation: 12 × (11 / 12-7 / 30) × 30 4 and 1 / 5-1 / 6 - (5 / 2-5 / 6) 4.38-1.56 + 0.62-0.44 13 out of 16 × (9 out of 13 × 17-9 out of 13) | Math enthusiast | Mathematical art

Simple calculation: 12 × (11 / 12-7 / 30) × 30 4 and 1 / 5-1 / 6 - (5 / 2-5 / 6) 4.38-1.56 + 0.62-0.44 13 out of 16 × (9 out of 13 × 17-9 out of 13)

13 out of 16 × (9 out of 13 × 17-9 out of 13)
=13/16*9/13*17-13/16*9/13
=9/16*17-9/16
=9/16*(17-1)
=9/16*16
=9

Simple algorithm of grade 4 56 * 7 + 77 * 4

Disassembly algorithm
Take 56 * 7 apart 50 * 7
6*7
Take 77 * 4 apart 70 * 4
7*4
And that's it
60*7+70*4 (60*7===50*7+6*7+4*7)
420+280=700

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