9+8+9+5+7+4+3+5+5+9+8/5=.................................
1+2+3+4+5+6+7+8+9+0+1+2+3+4+5+6+7+8+9+9+8+7+6+5+4+3+2+1+1+34+4+6+7+8+97+6+4+3+32+4+57+7+8+8+6+65+4+3+3+46+7+8+7+64+3+3+5+68+8+6+3+3+5+78+8+6+54+5+7+8+852+3+5+89+8+5+45+7×9×9×9×9×9×9×9×9×9×9×9×8×8×7×9×9×7×7×87×7×8×7×7×8×7×7×8
Tính nhẩm:
8 + 9 = ..... | 9 + 8 = ..... | 17 − 8 = ..... | 17 − 9 = ..... |
5 + 7 = ..... | 7 + 5 = ..... | 12 − 5 = ..... | 12 − 7 = ..... |
3 + 8 = ..... | 8 + 3 = ..... | 11 − 3 = ..... | 11 − 8 = ..... |
4 + 9 = ..... | 9 + 4 = ..... | 13 − 4 = ..... | 13 − 9 = ..... |
Phương pháp giải:
Tính nhẩm rồi điền số thích hợp vào chỗ trống.
Lời giải chi tiết:
8 + 9 = 17 | 9 + 8 = 17 | 17 − 8 = 9 | 17 − 9 = 7 |
5 + 7 = 12 | 7 + 5 = 12 | 12 − 5 = 7 | 12 − 7 = 5 |
3 + 8 = 11 | 8 + 3 = 11 | 11 − 3 = 8 | 11 − 8 = 3 |
4 + 9 = 13 | 9 + 4 = 13 | 13 − 4 = 9 | 13 − 9 = 4 |
8+9=17 9+8=17 17-8=9 17-9=8
5+7=12 7+5=12 12-5=7 17-7=5
1+1+1+1+2+2+2+3+3+3+3+4+4+4+4+5+5+5+5+6+6+6+6+7+7+7+7+8+8+8+8+9+9+9+9+10=
= (1+1+1+1)+(2+2+2)+(3+3+3+3)+(4+4+4+4)+(5+5+5+5)+(6+6+6+6)+(7+7+7+7)+(8+8+8+8)+(9+9+9+9)+10
4 + 6 + 12 + 16 + 20 + 24 + 28 + 32 + 36 + 10 =
= 188
1-2-3-4-5-6-7-8-9-0+4+9+1+2+3+4+5:3:5:6:67:8:96+7+8+9+9-2-3-4-5-6-7-8-9-2+4+2+1+3+4+5+6+7+9+0+8+67?
LÂY BÚA CHAC ĐẦU ĐUÔI HỎI =?
= 83,00000108
Tính:
8 + 1 = 7 + 2 = 6 + 3 = 5 + 4 =
1 + 8 = 2 + 7 = 3 + 6 = 4 + 5=
9 - 8 = 9 - 7 = 9 - 6 = 9 - 5 =
9 - 1 = 9 - 2 = 9 - 3 = 9 - 4 =
8 + 1 = 9 7 + 2 = 9 6 + 3 = 9 5 + 4 = 9
1 + 8 = 9 2 + 7 = 9 3 + 6 = 9 4 + 5= 9
9 - 8 = 1 9 - 7 = 2 9 - 6 = 3 9 - 5 = 4
9 - 1 = 8 9 - 2 = 7 9 - 3 = 6 9 - 4 = 5
Viết số thích hợp vào chỗ chấm:
2 = … + 1 |
6 = … + 4 |
8 = 5 + … |
10 = … + 2 |
3 = … + 2 |
6 = 3 + … |
8 = … + 4 |
10 = 7 + … |
4 = 3 + … |
7 = 6 + … |
9 = 8 + … |
10 = … + 4 |
4 = … + 2 |
7 = 5 + … |
9 = 7 + … |
10 = 5 + … |
5 = 4 + … |
7 = … + 3 |
9 = 6 + … |
10 = 10 + … |
5 = … + 2 |
8 = 7 + … |
9 = …+ 4 |
10 = 0 + … |
6 = 5 + … |
8 = … + 2 |
10 = 9 + … |
1 = … + 1 |
Lời giải chi tiết:
2 = 1 + 1 |
6 = 2 + 4 |
8 = 5 + 3 |
10 = 8 + 2 |
3 = 1 + 2 |
6 = 3 + 3 |
8 = 4 + 4 |
10 = 7 + 3 |
4 = 3 + 1 |
7 = 6 + 1 |
9 = 8 + 1 |
10 = 6 + 4 |
4 = 2 + 2 |
7 = 5 + 2 |
9 = 7 + 2 |
10 = 5 + 5 |
5 = 4 + 1 |
7 = 4 + 3 |
9 = 6 + 3 |
10 = 10 + 0 |
5 = 3 + 2 |
8 = 7 + 1 |
9 = 5+ 4 |
10 = 0 + 10 |
6 = 5 + 1 |
8 = 6 + 2 |
10 = 9 + 1 |
1 = 0 + 1 |
2=1+1 6=2+4 8=5+3 10=8+2
3=1+2 6=3+3 8=4+4 10=7+3
4=3+1 7=6+1 9=8+1 10=6+4
4=2+2 7=5+2 9=7=2 10=5+5
5=4+1 7=4+3 9=6+3 10=10+0
5=3+2 8=7+1 9=5=4 10=0+10
6=5+1 8=6=2 10=9+1 1=0+1
cop hết mạng kìa
Tính nhẩm:
8 + 5 = .... 8 + 7 = ....
8 + 4 = .... 8 + 2 + 3 = ....
8 + 2 + 5 = .... 8 + 2 + 2 = ....
9 + 5 = .... 9 + 7 = ....
9 + 8 = .... 9 + 1 + 4 = ....
9 + 1 + 6 = .... 9 + 1 + 7 = ....
Phương pháp giải:
Cộng các số lần lượt từ trái sang phải rồi điền kết quả vào chỗ trống.
Lời giải chi tiết:
8 + 5 = 13 8 + 7 = 15
8 + 4 = 12 8 + 2 + 3 = 13
8 + 2 + 5 = 15 8 + 2 + 2 = 12
9 + 5 = 14 9 + 7 = 16
9 + 8 = 17 9 + 1 + 4 = 14
9 + 1 + 6 = 16 9 + 1 + 7 = 17
13
12
15
14
17
16
15
13
12
16
14
17
1+2+3+4+5+6+7+8+9-1-2-3-4-5-6-7-8-9*1*2*3*4*5*6*7*8*9:1:2:3:4:5:6:7:8:9=???
14dm5cm=14,5dm;3dm7cm=3,7dm
chu vi hình chữ nhật đó là:
(14,5+3,7)x2=36,4(dm)
ĐS:36,4dm
14 dm 5 cm = 14,5 dm
3 dm 7 cm = 3,7 dm
Chiều rộng HCN là :
14,5 - 3,7 = 10,8 ( dm )
chu vi HCN là :
( 14,5 + 10,8 ) x 2 = 50,6 ( dm )
ĐS:..
Tính hợp lý:
a) ( -5/6 + 2/5) : 3/8 + ( 4/5 - 11/30) : 3/8
b) (-3/4 + 2/5) : 3/7 + ( 3/5 + -1/4) : 3/7
c)-13/18 . 5/8 + -5/18 . 2/9 + -13/18 . 3/8 + -5/18 . 7/9
d) -11/19 . 4/9 + -8/19 . 3/7 + -11/19 . 5/9 + -9/19 . 4/7
a: \(\left(-\dfrac{5}{6}+\dfrac{2}{5}\right):\dfrac{3}{8}+\left(\dfrac{4}{5}-\dfrac{11}{30}\right):\dfrac{3}{8}\)
\(=\left(-\dfrac{5}{6}+\dfrac{2}{5}\right)\cdot\dfrac{8}{3}+\left(\dfrac{4}{5}-\dfrac{11}{30}\right)\cdot\dfrac{8}{3}\)
\(=\dfrac{8}{3}\left(-\dfrac{5}{6}+\dfrac{2}{5}+\dfrac{4}{5}-\dfrac{11}{30}\right)\)
\(=\dfrac{8}{3}\cdot\dfrac{-25+36-11}{30}\)
=0
b: \(\left(-\dfrac{3}{4}+\dfrac{2}{5}\right):\dfrac{3}{7}+\left(\dfrac{3}{5}+\dfrac{-1}{4}\right):\dfrac{3}{7}\)
\(=\left(-\dfrac{3}{4}+\dfrac{2}{5}\right)\cdot\dfrac{7}{3}+\left(\dfrac{3}{5}-\dfrac{1}{4}\right)\cdot\dfrac{7}{3}\)
\(=\dfrac{7}{3}\left(-\dfrac{3}{4}+\dfrac{2}{5}+\dfrac{3}{5}-\dfrac{1}{4}\right)\)
\(=\dfrac{7}{3}\cdot0=0\)
c: \(\dfrac{-13}{18}\cdot\dfrac{5}{8}+\dfrac{-5}{18}\cdot\dfrac{2}{9}+\dfrac{-13}{18}\cdot\dfrac{3}{8}+\dfrac{-5}{18}\cdot\dfrac{7}{9}\)
\(=\left(-\dfrac{13}{18}\cdot\dfrac{5}{8}+\dfrac{-13}{18}\cdot\dfrac{3}{8}\right)+\left(-\dfrac{5}{18}\cdot\dfrac{2}{9}+\dfrac{-5}{18}\cdot\dfrac{7}{9}\right)\)
\(=-\dfrac{13}{18}\left(\dfrac{5}{8}+\dfrac{3}{8}\right)+\dfrac{-5}{18}\left(\dfrac{2}{9}+\dfrac{7}{9}\right)\)
\(=-\dfrac{13}{18}-\dfrac{5}{18}=-\dfrac{18}{18}=-1\)
d: Sửa đề: \(\dfrac{-11}{19}\cdot\dfrac{4}{9}+\dfrac{-8}{19}\cdot\dfrac{3}{7}+\dfrac{-11}{19}\cdot\dfrac{5}{9}+\dfrac{-8}{19}\cdot\dfrac{4}{7}\)
\(=\left(-\dfrac{11}{19}\cdot\dfrac{4}{9}+\dfrac{-11}{19}\cdot\dfrac{5}{9}\right)+\left(\dfrac{-8}{19}\cdot\dfrac{3}{7}+\dfrac{-8}{19}\cdot\dfrac{4}{7}\right)\)
\(=-\dfrac{11}{19}\left(\dfrac{4}{9}+\dfrac{5}{9}\right)+\dfrac{-8}{19}\left(\dfrac{3}{7}+\dfrac{4}{7}\right)\)
\(=-\dfrac{11}{19}-\dfrac{8}{19}=-\dfrac{19}{19}=-1\)
\(a.\left(-\dfrac{5}{6}+\dfrac{2}{5}\right):\dfrac{3}{8}+\left(\dfrac{4}{5}-\dfrac{11}{30}\right):\dfrac{3}{8}\)
\(=\left(-\dfrac{13}{30}\right):\dfrac{3}{8}+\dfrac{13}{30}:\dfrac{3}{8}\)
\(=\left[\left(-\dfrac{13}{30}+\dfrac{13}{30}\right)\right]:\dfrac{3}{8}\)
\(=0:\dfrac{3}{8}=0\)
\(b.\left(-\dfrac{3}{4}+\dfrac{2}{5}\right):\dfrac{3}{7}+\left(\dfrac{3}{5}+-\dfrac{1}{4}\right):\dfrac{3}{7}\)
\(=\left(-\dfrac{7}{20}\right):\dfrac{3}{7}+\dfrac{7}{20}:\dfrac{3}{7}\)
\(=\left[\left(-\dfrac{7}{20}+\dfrac{7}{20}\right)\right]:\dfrac{3}{7}=0:\dfrac{3}{7}=0\)
\(c.-\dfrac{13}{18}.\dfrac{5}{8}+-\dfrac{5}{18}.\dfrac{2}{9}+-\dfrac{13}{18}.\dfrac{3}{8}+-\dfrac{5}{18}.\dfrac{7}{9}\)
\(=\left(\dfrac{5}{8}+\dfrac{3}{8}\right).-\dfrac{13}{18}+\left(\dfrac{2}{9}+\dfrac{7}{9}\right).-\dfrac{5}{18}\)
\(=1.-\dfrac{13}{18}+1.-\dfrac{5}{18}=-\dfrac{13}{18}+-\dfrac{5}{18}=-1\)
\(d.-\dfrac{11}{19}.\dfrac{4}{9}+\dfrac{-8}{19}.\dfrac{3}{7}+-\dfrac{11}{19}.\dfrac{5}{9}+-\dfrac{9}{19}.\dfrac{4}{7}\)
\(=\left(\dfrac{4}{9}+\dfrac{5}{9}\right).-\dfrac{11}{19}+-\dfrac{24}{133}+-\dfrac{36}{133}\)
\(=-\dfrac{11}{19}+-\dfrac{60}{133}=-\dfrac{137}{133}\)