If the common factor is only 1, these two numbers must be prime numbers.

(

√

)

Both numbers are composite numbers and cannot be prime numbers.

(

√

)

Fill in the blanks:

The minimum error score with denominator of 9 is (

Nine out of nine

), the maximum true score is (

Eight out of nine

), the lowest score is (

One has one ninth.

)。

Fractions and general fractions are based on the basic properties of fractions: numerator and denominator expand or shrink by the same multiple (except 0) at the same time, and the fractional value remains unchanged. )

Put 2.8

2 and 7/8

1 and 15 points 14

1 and 20% 17

And 2

In order from small to large.

1 and 20% 17 < 1 and 15 points 14.

Application questions:

Forging a cubic iron block with a side length of 12cm into a rectangular iron block with a width of 16cm and 8cm respectively (excluding loss), what is its height?

12x12x12 =1728 (cubic centimeter)

Divide 1728 by 16 and then divide by 8= 18 (cm).

D: 18cm。

Colour all six sides of a cube red, and then cut it into eight cubes of equal size. Three small cubes painted red have (

eight

) block.