Exercise 1
I.5751969215316
1233 20 93 1 1349
II.21754 866 999
Three. neglect
Four. < = & lt& gt
V 1. 105/3=35 (unit/hour) 35*(3+2)= 175 (unit)
2.( 1) Take one kilogram of sugar each,14+/kloc-0+18 = 42 yuan.
42/3= 14 (yuan) (2)182/14 =13 (kg)
3.27*26+ 18=720 720/72= 10
Exercise 2
I.2 X-ray line segment X-ray countless X-rays 1 sharp 25 26
Ii.70120 75
Three. neglect
Four. neglect
5.13 6 The number of sides is not necessarily equal to the number of angles.
Intransitive verb 1. 10 hour-acute angle 6 hours-right angle 12 hours-rounded corner
3 o'clock-right angle 4 o'clock-obtuse angle
2. (Turn clockwise) Northeast, Southeast, Southeast, Southwest and Northwest, 90 45.
3. 180-40-90=50 degrees
Exercise 3
I.93 right angle 2 4 acute angle 12 5
Two. CBBC
Iii.60 90150 30
Four. neglect
V 1.20*8= 160 (decimeter) 2.
Exercise 4
I 105 1 16 530 14
Two. < & lt& lt& gt
(300-60)/6 = 40 18+ 120/20 = 24 56 1 1
Four. 1.(43+4 1)? 7= 12 (bar) 2. ( 180- 165)? 5=75 (meters) 3. 8+6? 4=32 yuan (100-20)? 4=20 (sheets) 4. 14? (□+3)-( 14? □+3)=39
Exercise 5
One. +47 0? 0 + 73 + 39 ? 2 ? 2 1
Two. 9 1 7060 1200 16 158 173 1800 9 10
3.④ ⑤ ② ② ④ ② ② ⑤
Four. 1.24*5*8=960 (tree) 2.520? 80? 5+520=552.5 (m) 3。
Exercise 6
I.37 2 vertical 180 540 yellow
Two. Bilateral bundle branch block
Three. 52 640
Four. 1.3* 15+3*4=57 (person) 2. 120? 40? 15=45 because 45
Exercise 7
I. 1.48 50 29 18 68 702. ( 1) 504 766 203 353628 (2) 13568 368 1 409 4758 1586 7930 68 699. 1 1 1 1 1 1 ( 1234+432 1)? 5= 1 1 1 1 (2)80 9800 998000 9999? 9999- 1=99980000
(1)5 bags 125 kg 8 bags of 200 kg (2)84 140 10 56? (84? 6)=4 because 4
120? 20? 100=600 (yuan) 120? 8? 48=720 (yuan)
Exercise 8
I.10/0 8000 53,453,040,530,00016900000669100000 ① ③ ②
Two. Below 90~99 60 100~98 95~88 88
○○○○○○○○○
Exercise 9
I. (1)1005172 24 80 23
(2)30 17 43(3)342 9 278 1380
( 1)
Three. neglect
Exercise 13
1. Multiplication and associative laws
Two. neglect
You should study hard.
( 1) 12* 14? 2 1=8 (yuan) 12* 14? 24=7 (pieces) (2)675 6 53 7 5 1
Exercise 14
1. Additive associative law1505965310103569
Two. CBCB
(1)24*50*3=3600 (yuan) (2) 16* 12*5=960 (tree) (3)180 250 95 320/kloc-0 20+ 1)*2+2*2= 16 (tree)
Exercise 15
I.241001009 50 80 24 80 202 371571434 900 780134.
Two. Shooting 15 Sharp15 205000500 900 million 5 8 400 2
Three. (1)45 120 60 (2) omitted
( 1) 18? 8? 6=24 (km) (2)3? 4+5= 17 (yuan) 50-(2? 5+3)=37 (yuan)
Exercise 16
I.9101616
Two. neglect
Table tennis 48 Basketball 25 10 1.92 There are 143 students in the fourth grade.
Four. 1.(257-82)? 25=7 (vehicles)
2.( 1).4? 12? 6=8 (articles) (2)4 boats with 6 people and 6 boats with 4 people.
Exercise 17
I.10530000000105300105 additive commutative law Boxer's 90 right-angle addition law ab=ba △ 5 2 1.
Two. BBCA
Three. 10 13 16 17 22 16? 3+ 1=49 (root)
( 106- 1)? 3=35 (pieces)
( 1) 12? 3? 25=900 yuan (2) 12? 15? 10= 18 (page)
Exercise 18
I. 20040510 20405165260+(16? 5)= 340(T . E . H)(E . n . z . H)(E . H)(A . k . x) 144 24
Two. 129 400 1020
Three. neglect
Four. 1. 135? (3? 5)=9 (times)
2.( 1)38- 15? 2=8 yuan ②36? 8+2? 15=3 18 (yuan) Because 3 18 yuan is greater than 300 yuan, it is not enough.
3.(275- 1 10)? ( 1 10? 2)=3 (hours)
I recommend it carefully.