Ten simple arithmetic questions, fourth grade. Urgent need! Thank you~~~~~

Ten simple arithmetic questions, fourth grade. Urgent need! Thank you~~~~~

12.5*0.12*8

There are four simple arithmetic problems in grade six
Add, subtract, multiply and divide each

Plus: 5 + 2 + 5=
Minus: 10-2-2=
Multiply: 5 × 5 × 2=
Except: 10 △ 2 △ 5=
It's too simple. Vote!

Four simple calculation questions, before 5:30,
①1+2+3+4+5+····+98+99+100
②50+51+52+·····+249+250
③1+2+4+8+16+····+1024
④ 8 + 4 + 2 + 1 + Half + 256

①1+2+3+4+5+····+98+99+100
=(1+100)×100÷2
=5050
②50+51+52+·····+249+250
=(50+250)×（250-50+1）
=300×201
=60300
③1+2+4+8+16+····+1024
=（1+1024）×1204÷2÷2
=262400
④ 8 + 4 + 2 + 1 + Half + 256
=8×（1-1/256）÷（1-1/2）
=16-1/16
=15 and 15 / 16

Ask a simple question
1234567891*1234567891-1234567890*1234567890

Let 1234567891 = x, then 1234567890 = X-1
Original formula = x ^ 2 - (x-1) ^ 2 = 2x-1 = 1234567891 * 2-1 = 2469135781