Đề thi giữa kì 2 Toán lớp 4 Cánh diều – Đề 9 (có đáp án)

$\frac{11}{24}$ +$\frac{15}{24}$ = $\frac{11+15}{24}$= $\frac{26}{24}$= $\frac{13}{12}$

$\frac{21}{20}$ - $\frac{13}{20}$ = $\frac{21-13}{20}$= $\frac{8}{20}$= $\frac{2}{5}$

 $\frac{1}{3}$  + $\frac{7}{15}$ = $\frac{5}{15}$  + $\frac{7}{15}$= $\frac{12}{15}$= $\frac{4}{5}$ 

$\frac{33}{35}$ - $\frac{18}{35}$ = $\frac{33-18}{35}$= $\frac{15}{35}$= $\frac{3}{7}$

a) $\frac{8}{5}=\frac{72}{40}$

Ta có: $$\frac{72}{40}=\frac{72:8}{40:8}=\frac{9}{5}$$

So sánh: $$\frac{8}{5}<\frac{9}{5}$$

Vậy $$\frac{8}{5}<\frac{72}{40}$$

c) $\frac{100}{15}=\frac{20}{3}$

Ta có: $$\frac{100}{15}=\frac{100:5}{15:5}=\frac{20}{3}$$

So sánh: $$\frac{20}{3}=\frac{20}{3}$$

Vậy $$\frac{100}{15}=\frac{20}{3}$$

b) $\frac{14}{37}=\frac{42}{111}$

Ta có: $$\frac{14}{37}=\frac{14\times 3}{37\times 3}=\frac{42}{111}$$

So sánh: $\frac{42}{111}=\frac{42}{111}$

Vậy $\frac{14}{37}=\frac{42}{111}$

c) $\frac{200}{50}=\frac{2}{5}$

Ta có: $$\frac{200}{50}=\frac{200:10}{50:10}=\frac{20}{5}$$

So sánh: $$\frac{20}{5}>\frac{2}{5}$$

Vậy $$\frac{200}{50}>\frac{2}{5}$$

15 m² 7 dm² = 1 507 dm²

Giải thích:

15 m² 7 dm² = 15 00 dm² + 7 dm²

                     = 1 507 dm²

12 500 cm² = 120 dm² 500 cm²

Giải thích:

12 500 cm² = 12 000 cm² + 500 cm²

= 120 dm² + 500 cm²

= 120 dm² 500 cm²

21 dm² 10 cm² = 211 000 mm²

Giải thích:

21 dm² 10 cm² = 210 000 mm² + 1 000 mm²

                        =   211 000 mm²

2 180 dm² = 21 m² 80 dm²

Giải thích:

2 180 dm² = 2100 dm² + 80 dm²

= 21 m² + 80 dm²

= 21 m² 80 dm²