1, 3+4 = 73+5 = 83+6 = 94+5 = 94+6 =105+6 =1/singular: 2/3 even: 1/3.

3× 4 =123× 5 =153× 6 =184× 5 = 204× 6 = 245× 6 = 30 odd number: 1/6 even number: 5/6.

A: Choose the third option.

2.6× 5 = 305× 4 = 2030+20-(1+2+3+4+5+6+7+8+9) = 5 a: The card in the middle is 5.

3、(7- 15× 1/3)×5? ×3. 14= 157 (cubic centimeter) A: The original volume of those two pieces of ice is 157 cubic centimeter.

4.100-100 ÷ 40× 30 = 25 (m) 25 ÷ (40+30) =100/7 (m) A: My son is still 25 meters away from the finish line, so he is at the finish line.