A simple calculation method of 128 × 43 × 8 in the first semester of the fourth grade of primary school

128x43x8
=(125+3)x43x8
=[(125x8)+(3x8)]x43
=[1000+24]x43
=1000x43+24x43
=43000+1032
=44032
I'm right. If I don't believe it, I'll use a calculator. I'm in grade six

The approximate number is -0.0450, 20000, 20000, 3.14 times the 5th power of 10, and -6.800 times the 4th power of 10. It is accurate to a few digits, a few significant numbers
It's urgent now

-0450, accurate to 10000, significant number: 3
20000: 10000, 1
2000. 1000. 1
3.14 times 10 to the fifth power. Thousand bits. 3
-The fourth power of 6.800 times 10

7 / () = 70% = () divided by 50 = 28: () = 70%

7 / (10) = 70% = (35) divided by 50 = 28: (40) = 70%

When Xiao Hong calculates a division formula, she takes the divisor 9 as 6 and gets a quotient of 15. What is the correct quotient?

1. Correct divisor: 6 × 15 = 90
2. Correct quotient: 90 △ 9 = 10

When doing an addition problem, Xiao Hong regards 6 as 9 and 8 as 3. The result is 123
What's the correct result? We have to calculate it

One of the addends is regarded as 86, because it is wrongly regarded as 39
So the result will be less 86-39 = 47
So the correct result is 123 + 47 = 170

When Xiao Hong calculates a division formula, she carelessly writes 2 on 482 bits of the divisor as 0. The result is that the quotient is 16. What is the correct quotient?

482/(480/16)
=482/30
=16.2

When Xiao Hong calculates a division formula, she writes the divisor 34 into 43. The result shows that the quotient is 15 and the remainder is 35. What is the correct result?

Let the divisor be x, then x △ 43 = 15 and 35
So x = 43 × 15 + 35 = 680
The correct result is 680 △ 34 = 20

There is an addition formula. Xiao Hong mistook it for subtraction. The result is 8.6, which is 10.4 less than the correct answer
Analyze the reasons

Let two addends be x.y
X+Y=8.6+10.4
x-y=8.6
The solution is x = 13.8
Y=5.2

5 6 7 10 is 24

I usually like to play this by myself, ha ha
But there is no solution

5. 6, 7 and 10 are combined to form an expression with the result of 24

5*6-7+lg10
=30-7+1
=24

A simple calculation method of 128 × 43 × 8 in the first semester of the fourth grade of primary school