55-44= 33-27= 36- 14= 87-77=

36+42= 15+55= 24+ 16= 16+ 16=

34+8= 49+5= 42+3 1= 24+ 16=

44-8= 34-5= 83-6= 45-23=

43- 12= 63- 12= 53-40= 89-85=

96-50= 78-23= 56-24= 89-58=

43+ 25= 12+ 46= 47+ 13= 25+ 14=

18+20= 36+2 1= 30+45= 27+ 12=

24+25= 35+ 12= 40+ 58= 26+ 13=

50-46= 72-22= 45- 13= 36-27=

14- 13= 58-47= 39-27= 15-9=

60+ 32= 8 1+ 12= 34+25= 17+ 12=

9+38= 60-35= 89-80= 43+27=

40- 17= 30+22= 78-50= 28+32=

67-24= 65-6= 77-34= 96-6 1=

75-25= 54- 14= 67-56= 56-9=

42+9= 43+3= 48+4= 25+3=

33+4= 23+9= 18+ 12= 9+26=

25+8= 24+7= 24+6= 38+7=

32-20= 53-20= 46-20= 43-2 1=

Second, I'll fill in the blanks. (18)

1. I will draw a line on the counter to indicate the result, and then fill in the blanks. (6 points)

2. I'll just fill in ○? & gt？ 、? & lt？ 、? =? . (6 points)

45+26○70 54○28+ 16 80- 16○80+ 16

90-28○60 43○93-50 43+26○90-2 1

3.4 6 Thinking: One digit () minus () is not enough, so we will count () from ten digits and get 6 points.

-2 7 bits () minus () equals ();

() Ten digits () minus () minus () equals ().

Third, write the following questions. (18)

45+26= 74-29= 53- 17=

34+48+ 13= 35+26-24= 79-8-25=

Fourth, estimate the connection. (6 points)

2 1+28 is less than 50.

23+59

89-52

Greater than 80

45+37

Five, solve the problem (38 points)

1. Mom gives money to Mingming 42 yuan and Dad gives money to Mingming 39 yuan. Now it is obviously about () yuan. (3 points)

2.2 Class (1) students made 80 small red flowers and gave them to Class 2 (22) and Class 2 (3) with 38 flowers. Now, about () flowers have been sent out, and there are about () flowers left. (6 points)

3. Trucks, vans and buses

45 vehicles, 36 vehicles, 12 vehicles

(1) How many trucks are there than vans? (4 points)

A: There are more trucks than trucks.

(2) How many trucks and buses are there? (4 points)

There are vans and buses.

(3) How many buses are less than trucks? (4 points)

Answer: There are fewer buses than trucks.

(4) Can you propose a parallel solution to any mathematical problem? (7 points)