They (unload)are unloading the vegetables now.

My father (listen)is playing to the radio now.

The sun (warm)warms the air and (give)gives us light.

She (go) goes to school everyday.

He (meet)will meet the dentist next week.

They usually (not go)doesn't go to school by bike.

Minh (play)is playing chess with Nam at the moment?

My old friend (write)writes to me twice a month.

Bi often (not phone)doesn't phone to me.

Look! The ball (fall)is falling down.

She (not listen)isn't listening to the radio now.

He (play)is playing table tennis at the moment.

Hung often (not go)doesn't go camping in the summer.

Son (write)writes to their friends every summer holiday?

They (plant)will plant trees along this street next month.

He often (pick)picks his friend up at the train station.

Do you usually (watch)watch TV in the evening?

Mai and Hang (not play)aren't playing the game at the moment.

They always (not go)don't go to the school by train.

They (plant)plant trees in the early year

He (not study)isn't studying Math at the moment.

I (play)am playing video games but my sister (watch)is watching TV now

l often (read)read a book.

We (watch)watch T.V every morning.

Mai and Lan (play ) play games after school.

Where (be）is your father now?

She is cooking and we（do）are doing the housework

He isn't in the room. He (play）is playing in the garden.

They (play）are playing volleyball now

Mai（be )is tired now..

Where is your father? He（watch)is watching T.V

Sao and Mai (do）is doing the housework now

How do you（go）go to school every day?

Nam（go）goes to work by car every day

Look！The teacher（come)is coming

254 × 399 - 145 / 254 + 399 × 253

= (253 + 1) × 399 - 145 / 254 + 399 × 253

= 253 × 399 + (399 - 145) / 254 + 399 × 253

= 253 × 399 + 254 / 254 + 399 × 253

= 1

\(10^9+10^8+10^7=10^6.10^3+10^6.10^2+10^6.10=10^6\left(1000+100+10\right)=10^6.1110\)

                                     \(=10^6.222.5\) (ĐPCM)

\(S=2^2.1+2^2.2^2+2^2.3^2+....+2^2.10^2\)

\(S=2^2.\left(1^2+2^2+3^2+...+10^2\right)\)

\(S=4.385=1540\)

Cách 1:

B=1/2+1/4+1/8+1/16+1/32+1/64

B=1-1/2 + 1/2-1/4 + 1/4-1/8 +1/8-1/16 + 1/16-1/32 + 1/32-1/64

B=1-1/64

B=63/64

Cách 2:

B=1/2+1/4+1/8+1/16+1/32+1/64

B=1/2¹+1/2²+1/2³+1/2⁴+1/2⁵+1/2⁶

2B=1+1/2¹+1/2^2+1/2^3+1/2^4+1/2^5

2B-B=1-1/2^6

B=1-1/64 

B=63/64

Sắp xếp các từ sau thành câu hoàn chỉnh :

1. skiing / they / go / family / with / the / in / usually / the / winter

=> They usually go skiing with the family in the winter.

2. my / is / drink / apple juice / favorite

=> My favourite drink is apple juice.

3. play / let's / volleyball

=> Let's play volleyball.

4. from / her / France / friend

=> Her friend from France.

Nếu bỏ chữ số 1 bên trái số lớn thì hiệu hai số là 100

Số lớn là:

(182 + 100) : 2 = 141

Số bé là:

182 - 141 = 41

Đáp số : 141 và 41

gọi số bé là: ab ; số lớn là: 1ab

Hiệu hai số là: 1ab - ab = 100

Số lơn là: (182 + 100) : 2 = 141

Số bé là: 141 - 100 = 41

Từ 1 đến 9 có : ( 9 - 1 ) : 1 + 1 = 9 ( số ) => có 9 x 1 = 9 ( chữ số )

Từ 10 đến 99 có : ( 99 - 10 ) : 1  1 = 90 ( số ) => 90 x 2 = 180 ( chữ số )

Từ 100 đến 148 có : ( 148 - 100 ) : 1 + 1 = 49 ( số ) => có 49 x 3 = 147 ( chữ số )

cần phải viết là : 9 + 180 + 147 = 336 ( chữ số )

Đáp số : 336 chữ số