The first time (3,3,3) and the second time (1, 1, 1)

(4) Because Friday, Saturday, Sunday and 14 are connected,

If there is 3 1 day, there must be three days (connected on Friday, Saturday and Sunday, or connected on Saturday and Monday,)

So there are only 30 days in this month, Saturday, 1, Thursday, 6th.

4(7 kg) 3×2+ 1=7

5.(254) If the minuend is over-calculated (8-3=5), it should be removed; if the minuend is over-calculated by 60, it should be added (199+3-8+60=254).

6( 1 m) has 7 1 m. Two and a half meters.

7. The conditions are wrong (middle school students may not know it, length+width =√6, length =2, length =(√6+2)/2, width =(√6-2)/2).

8.(50) (4+2)×2- 1]×2=26, (26- 1)×2=50.

9.(A) The same in the first year, but 65,438+million; in the second year, A is10+2 =120,000, and B is (5+0.5) × 2 =10,000.