one+two

1+2

=3

three

1/a/78,5cm2

1/b/0,5024dm2

1/c/39,57185m2

2/a/122,65625cm2

2/b/415,265dm2

2/c/15,89625m2

3/6358,5

12 * 7  + X =  89

84 + X       = 89

X              =  89 - 84

X              =  5

Fill in the blank with the suitable number (Note: write decimal number with "the dot" between number part and fraction part. Example: 0.5)

Câu 1:
4.62 x 7.5 = 7.5 x 4.62
The missing number is  
(Write your answer as a decimal in the simplest form)

Câu 6:
163.4cm - 45.24cm = 118.16 cm.
The missing number is {}
(Write your answer as a decimal in the simplest form)

Câu 9:
A rectangular garden is 25.04m long, the width is 3/4 of the length. Find the perimeter of the garden?
Answer: 87.64 m
(Write your answer as a decimal in the simplest form)

Câu 10:
A rectangle has width of 18.25m. The length is 4.75m longer than the width. Find the area of that rectangle?
Answer: The area of that rectangle is 419.75 m².  
(Write your answer as a decimal in the simplest form)

Câu 3:
Calculate: 4.72 x 100 = 472

Câu 8:
Calculate: 5dm7cm + 8m4dm = 8.97
(Write your answer as a decimal in the simplest form)

Câu 2:
Calculate: 7.34 - 6.27 = 1.07
(Write your answer as a decimal in the simplest form)

Câu 4:
Calculate: 21.8 x 5 = 109

Câu 2:
Calculate: 28.2 + 31.95 = 60.15
(Write your answer as a decimal in the simplest form)

Câu 4:
Calculate: 36.26 x x 10 = 362.6
(Write your answer as a decimal in the simplest form)

Câu 5:
Calculate: 42.75 x 39 - 42.75 x 29 = 427.5
(Write your answer as a decimal in the simplest form)

Câu 9:
Calculate: (48.6 x 2.4 - 24.3 x 4.8) x 20.15 x 46.92 = 0

Câu 3:
Calculate: 57.71 - 35.29 = 22.42
(Write your answer as a decimal in the simplest form)

Câu 1:
Calculate: 84.4 : 8 = 10.55
(Write your answer as a decimal in the simplest form)

Câu 6:
Calculate: 345.58 x 4.9 - 45.58 x 4.9 = 1470

Câu 5:
Find the value of 2.8 x (4.3 + 8.1).
Answer: 34.72
(Write your answer as a decimal in the simplest form)

Câu 8:
Find the value of x such that x + 8.04 - 9.34 = 16.31.
Answer: x = 17.61
(Write your answer as a decimal in the simplest form)

Câu 4:
Find the value of x such that x + 47.92 = 89.27.
Answer: 41.35
(Write your answer as a decimal in the simplest form)

Câu 9:
Half of the perimeter of a rectangular school yard is 0.24km. The width is 1/2 of the length. Find the area of the yard in square meters?
Answer: The area of the yard is 12800 m²
 

Giải:

Câu 3:
Multiply: 2.34 x 7 = 16.38
(Write your answer as a decimal in the simplest form)

Câu 5:
The sum of the smallest 3-digit number and 27.02 is 127.02
(Write your answer as a decimal in the simplest form)

Câu 7:
The sum of two numbers is 10.54 and their difference is 1.94. The greater number is 6.24
(Write your answer as a decimal in the simplest form)

Câu 7:
The value of 5.25 4.2 +8.91 is 30.96
(Write your answer as a decimal in the simplest form)

Câu 10:
Tom bought 3.5kg apples and 2.4kg oranges. If the apples cost 5 dollars per kilogram and the oranges cost 6 dollars per kilogram. How much did Tom spend altogether?
Answer: 31.9 dollars
(Write your answer as a decimal in the simplest form)

Câu 10:
What is the difference between the largest and the smallest possible distinct 4-digit number that you can make from four digits 0, 4, 2 and 3?
Answer: Their difference is 2286

Bài thi số 3: Vượt chướng ngại vật

Calculate: 4.75 x 8.2 : 2 = … Answer: 19.475

Calculate: 8.4 x 2.6 - 8.92 = … Answer: 12.92

Calculate: 11.13 + 13.15 + 15.17 + 17.19 + 19.21 + 21.23 + 23.25 + 25.27 + 27.29 + 29.31 + 31.33 = …hm. Answer: 233.53

Convert: 9km 72m = …hm. Answer: 90.72

Find two numbers if their sum is 13.96 and their difference is 2.72 Answer: 8.34 and 5.62

If: x x 4 = 21.64 then 2.5 x x = … Answer: 13.525

If: x is a natural number and x > 25.092 then the smallest value of x is … Answer: 26

Multiply: 0.025 x 400 = … Answer: 10

Multiply: 37.92 x 0.01 = … Answer: 0.3792

Multiply: 241.82 x 0.1 = … Answer: 24.182

There are 9 packages of rice which weigh 403.74kg. How many kilograms do 15 such packages of rice weigh? Answer: 672.9

There are 362 tonnes of rice in a store. They took out 271.48 tonnes of rice. How many tonnes of rice are left in the store? Answer: 90.52

2005 + 1999 = 4004

Ta thấy khi chia số thứ nhất cho số thứ hai thì đc 4 dư 5

Vậy số thứ nhất gấp 4 lần số thứ hai và cộng thêm 5

Do đó ta có:

120-5=115

Áp dụng bài toán tổng tỉ

Tổng số phần = nhau là

4+1=5

Số thứ nhất=

\(\frac{115}{5}.4+5\)=97

Số thứ hai=

\(\frac{115}{5}.1\)=23

1332

ai tk mk

mk tk lại

mk hứa

yên tâm

số bé bằng 112

số lớn bằng 672

gap ruoi la 3/5 day

\(24+\frac{x}{50}+x=\frac{3}{5}\)

           \(\frac{x}{50}+x=\frac{3}{5}-24\)

    \(\left(\frac{1}{5}+1\right)x=-\frac{117}{5}\)

                  \(\frac{6}{5}x=-\frac{117}{5}\)

                       \(x=\left(-\frac{117}{5}\right):\frac{6}{5}\)

                       \(x=-\frac{39}{2}\)