1、5.7+9.8=5.7+ 10( )0.2
2、63.8- 10.3=63.8- 10( )0.3
3, the number of 0.4 greater than 3.92 is ()
4. The number less than 4.93 times 1.5 is ()
5. Half of () is 6.3.
6. The number A is 10.9, which is 0.852 more than the number B. The sum of the number A and the number B is ().
7, less than 1, the largest three decimal places minus the smallest four decimal places is ().
According to 18.3-9.8 = 8.5, two formulas can be written: 18.3 = () and 9.8 = ().
9, less than 10 yuan, 1.7 yuan is () yuan.
10, three decimal places minus two decimal places, and the difference is () decimal places.
Second, judgment.
1, the meaning of decimal addition and subtraction is the same as that of integer addition and subtraction. .......................... ()
2. To calculate the addition and subtraction of decimals, first align the two ends of each number with ....................................... ().
3. There are 9 decimal places greater than 0. 1 less than 0.2 ..................................................... ().
4. The number of A is 1.45, which is 0.45 less than that of B, and the number of B is 1 ....................................... ().
5. Calculate 8 tons of 80kg-3 tons of 800kg = 8.8-3.8 = 5 (tons). .......................................................................................................................................
6,5.42+3.78 = 9.20, and the 0 at the end of the decimal part should be removed, so it is equal to 9.2 ..................... ().
7、0.78-0.078=0………………………………………………………………( )
8、6.43-6.2-0.2=0.03………………………………………………………( )
Third, choose
1, 5.7+8.9+8.3 = 5.7+8.3+8.9 Used ().
A additive commutative law b additive associative law c additive commutative law associative law.
2, 4 Angle 6 points +7 yuan 4 points = ()
A 7 yuan 8.6 points B 12 yuan C 7.50 yuan.
3. Rewrite 2 meters and 3 centimeters into meters. The decimal number is () meters.
A 2.3 B 2.03 C 2.003
4. Calculate the decimal subtraction, accidentally increase the subtraction by 3.2, and the minuend remains the same, then the difference () he calculated.
A increases by 3.2 B and decreases by 3.2 C.
5. 10 subtract () 0. 1 continuously, and the result is 0.
A 100 B 10 C 1000
6. When two numbers are divided by 9, the minimum divisor is ().
A 9 B 10 C 1 1
8. One addend is three decimal places, the other addend is two decimal places, and the sum is () decimal places.
A two, b three, c five
Four calculations
1, oral calculation
0.7+0.9= 0.8+0.6= 8.24+3.76= 4. 1-3.8=
14+0.78= 14.6-0.34= 1.3+8.56= 0.8-0.55=
4-0.04= 1-0.03= 30.5+3.05= 0.8-0.45=
0.78+2.2= 5-0.08= 3.25+0.75= 10-0. 1=
2, column vertical calculation
8.65-6.3 1= 10-7.64= 13.6+8.46= 0.99+ 1. 1=
3. Simple calculation
45.55-(6.82+ 15.55) 34.52- 17.87- 12.23 4.57+3. 17+3.43+5.83
23.75-8.64-3.36 17.83-9.5-7.83-0.5 3.45+8.7+ 16.55+ 1.3
8.54-5.96 27.38-5.34+2.62-4.66 2 1.63-(8.5+9.63)
4, column calculation
What is the difference between the sum of 7.07 and 3.45 minus them?
What is the result of adding 3.54 times 4.3 to the number less than 15.7?
The number A is 48.3, which is more than the number B 12.7. What is the sum of the two numbers?
How much is 9.8 more than the sum of 2.34 and 4.36?