L, a number with hundreds of millions of digits is 5, 10000, the highest digit of each digit is also 5, and all other digits are 0. This number is written as (500050005), and the mantissa after omitting 10000 is (50005 million).
The decimal unit of 2.0.375 is (0.00 1), and it has (375) such units.
3.6.596596 ... is an (infinite) circulating decimal, which is simply called (), and it is (6.60) to keep two decimal places.
4. You can fill in,) 1.3 hours 1 km () 7 km.
10, right triangle, with one acute angle of 35 and the other acute angle of (55).
1 1, a 2-meter-long straight cylindrical wood with a cross section of 2 decimeters, with a surface area less than the original 12.56 square decimeter. The original bottom area of cylindrical wood was (6.28) square decimeter and its volume was (125.6) cubic decimeter.
12. Add 3g of salt and 7g of water to the salt water with a salt content of 30%, and the ratio of salt to water in the salt water is (3:7).
Second, the judgment question. Put √ in brackets for the right and × for the wrong. (65438+ 0 points for each question, ***5 points)
1, the score with a large fraction unit must be greater than the score with a small fraction unit. ( × )
The greatest common divisor of 2,36,48 is 12, and the common divisor is 1, 2,3,4,6, 12. ( √ )
The weight of a ping-pong ball is about 3kg. ( × )
A circle has countless radii, and they are all equal. ( √ )
5. Multiply the former item of the ratio and divide the latter item by 2 to reduce the ratio by 4 times. ( )
Third, multiple choice questions. Fill in the brackets with the serial number of the correct answer. (2 points for each question, *** 10)
1, divided by two numbers, the quotient is 50 and greater than 30. If the dividend and divisor are reduced by 10 times at the same time, the quotient and remainder obtained are (2).
(1) Quotient 5+3 (2) Quotient 50+3 (3) Quotient 5+30 (4) Quotient 50+30
2.4x+8 is misspelled as 4 (x+8), and the result is better than the original (3).
(1) More 4 (2) Less 4 (3) More 24 (4) Less 24
3. On a map, the actual distance of 90km is represented by 2cm, and the scale of this map is ().
( 1) (2) (3) (4)
4. A rectangle is 6 cm long, 3 cm wide and 2 cm high. The ratio of minimum surface area to surface area is (3).
l:3(2) 1:6(3)l: 12(4)l:24
5. The number A is 840. What is the number B? If the formula for finding the number b is 840 ÷ (L+), then the supplementary condition on the horizontal line is (3).
(1) A number is greater than B number (2) A number is less than B number.
(3) The number of B is more than that of A; (4) the number of b is less than that of a.
Fourth, the calculation problem. (***35 points)
1, a number written directly. (5 points)
529+ 198=727 305- 199= 106 2.05×4=8.2
8× 12.5%= 1 + ×0= =
0.68+ +0.32= 1 ÷ +0.75×8=
2. Use a simple method to calculate. (6 points)
25× 1.25×32 (3.75+4. 1+2.35)×9.8
=25 ×4 ×( 1.25×8) = 10.2×9.8
= 100× 10 = 10.2×( 10-0.2)
= 1000 = 10.2× 10- 10.2×0.2
=99.96
3. calculation. (l2)
5400-2940÷28×27 (20.2×0.4+7.88)÷4.2
= 5400- 105×27 =(8.08+7.88)÷4。 2
=5400-2885 = 15.96÷4.2
=25 15 =3.8
( )÷ + 10÷[ -( ÷ + )]
4. Column calculation. (6 points)
(l) l) What is the quotient of the product of 0.6 and 2.25 minus the difference between 3.2 and l.85?
(3.2- 1。 85)÷(0.6×2.25)= 1
(2) A number is that 1.5 is more than 25% of 30. Find this number.
There should be a score, so you can't do the problem.
5. Calculate the volume. (Unit: meter) (3 points)
No charts
6. Each grid in the figure below represents 65,438+0 square centimeters. Please draw a parallelogram, triangle and trapezoid with an area of 6 square centimeters by using the points and lines on the grid paper as much as possible, and make the heights respectively. (3 points)
No charts
Fifth, the application problem. (30 points)
1, the perimeters of a rectangle and a circle are equal. It is known that the length of a rectangle is 10 cm and the width is 5.7 cm. What is the area of a circle?
( 10+5.7)×2=3 1.4cm
31.4÷ 3.14÷ 2 = 5cm.
3. 14×5×5=78.5 cm2
The area of this circle is 78.5 square centimeters.
There are some problems that can't be done because of lack of marks or no pictures.