1. Find the surface area and volume of a cuboid (unit: decimeter) 4%.

a=8 b=5 c=4

2. Off-model calculation (simplified to simplified) 12%

6/7+2/ 15+ 1/7+ 13/ 15 19/2 1+5/7-3/ 14

2/3+5/9-2/3+5/9

8/9-( 1/4- 1/9)- 3/4

3. Use 4% to find the greatest common divisor and the least common multiple of the following groups.

Articles 24 and 36

18, 24 and 40 (only the least common multiple)

4. Text problem 6%

What is the sum of 5/9 and 7/ 18 minus 1/2?

Subtract the difference between 7/ 15 and 7/30 from a number and the result is 2/3. What's this number? (Equation solving)