Gọi số cần nhân với 3 là \(x\).

Ta có: \(3\cdot x=555555\\ x=555555:3\\ x=185185\)

⇒ Phải nhân 3 với 185185 để được kết quả là 1 số tự nhiên viết bằng 6 chữ số 5.

1. That's a bear.

2. I can see 7 windows.

3. Look at the sun.

4. She's eating.

\(\dfrac{23}{9}+\dfrac{67}{9}=\dfrac{23+67}{9}=\dfrac{90}{9}=10\)

\(\dfrac{24}{15}+\dfrac{36}{15}=\dfrac{24+36}{15}+\dfrac{60}{15}=4\)

\(\dfrac{9}{6}+5=\dfrac{9}{6}+\dfrac{30}{6}=\dfrac{9+30}{6}=\dfrac{39}{6}=\dfrac{13}{2}\)

\(7+\dfrac{20}{9}=\dfrac{63}{9}+\dfrac{20}{9}=\dfrac{63+20}{9}=\dfrac{83}{9}\)

\(\dfrac{26}{18}+\dfrac{7}{9}=\dfrac{26}{18}+\dfrac{14}{18}=\dfrac{26+14}{18}=\dfrac{40}{18}=\dfrac{20}{9}\)

\(\dfrac{5}{7}+\dfrac{16}{14}=\dfrac{10}{14}+\dfrac{16}{14}=\dfrac{10+16}{14}=\dfrac{26}{14}=\dfrac{13}{7}\)

\(\dfrac{8}{20}+\dfrac{6}{5}=\dfrac{8}{20}+\dfrac{24}{20}=\dfrac{8+24}{20}=\dfrac{32}{20}=\dfrac{8}{5}\)

\(\dfrac{9}{7}+\dfrac{11}{35}=\dfrac{45}{35}+\dfrac{11}{35}=\dfrac{45+11}{35}=\dfrac{56}{35}=\dfrac{8}{5}\)

\(\dfrac{3}{36}+\dfrac{8}{6}=\dfrac{3}{36}+\dfrac{48}{36}=\dfrac{3+48}{36}=\dfrac{51}{36}=\dfrac{17}{12}\)

\(\dfrac{25}{9}+2=\dfrac{25}{9}+\dfrac{19}{9}=\dfrac{25+19}{9}=\dfrac{44}{9}\)

What is the height of this mountain?

⇒ How high is this mountain?

1. Look at the pannier.

2. I can see a tiger.

3. The truck is moving.

4. Lucy is watching a football match.

5. How many mangoes can you see?

B. tourist attractions

3,75 phút = 225 giây

12 phút = 0,2 giờ

5 giờ 18 phút = 5,3 giờ

2 giờ 54 phút = 2,9 giờ

2093 kg = 20 tạ 930 hg

2 ha 145 m² = 201,45 dam

Bài 1: Tính

\(\dfrac{9}{5}+\dfrac{7}{15}=\dfrac{27}{15}+\dfrac{7}{15}=\dfrac{34}{15}\)

\(\dfrac{7}{3}\cdot1=\dfrac{7\cdot1}{3}=\dfrac{7}{3}\)

\(\dfrac{8}{2}-\dfrac{5}{6}=\dfrac{24}{6}-\dfrac{5}{6}=\dfrac{19}{6}\)

\(1\cdot\dfrac{7}{4}=\dfrac{1\cdot7}{4}=\dfrac{7}{4}\)

\(\dfrac{7}{2}\cdot\dfrac{8}{5}=\dfrac{7\cdot8}{2\cdot5}=\dfrac{56}{10}=\dfrac{28}{5}\)

\(\dfrac{9}{5}\cdot\dfrac{5}{3}=\dfrac{9\cdot5}{5\cdot3}=\dfrac{45}{15}=3\)