Arrange the fractions in ascending order.

2.1 [tex]\quad \frac{3}{5} ; \frac{12}{15} ; \frac{7}{10} ; \frac{18}{20} ; \frac{21}{25}[/tex]

2.2 [tex]\quad \frac{7}{10} ; \frac{12}{100} ; \frac{65}{100} ; \frac{5}{10} ; \frac{23}{100}[/tex]

2.3 [tex]\quad \frac{3}{10} ; \frac{4}{5} ; \frac{40}{100} ; \frac{8}{20} ; \frac{21}{50} ; \frac{35}{100}[/tex]

Let's arrange the fractions in ascending order for each part using the given numerical results.

### Part 2.1
The fractions given are:
- [tex]\( \frac{3}{5} \)[/tex]
- [tex]\( \frac{12}{15} \)[/tex]
- [tex]\( \frac{7}{10} \)[/tex]
- [tex]\( \frac{18}{20} \)[/tex]
- [tex]\( \frac{21}{25} \)[/tex]

The equivalent decimal values for these fractions are:
- [tex]\( \frac{3}{5} = 0.6 \)[/tex]
- [tex]\( \frac{7}{10} = 0.7 \)[/tex]
- [tex]\( \frac{12}{15} = 0.8 \)[/tex]
- [tex]\( \frac{18}{20} = 0.9 \)[/tex]
- [tex]\( \frac{21}{25} = 0.84 \)[/tex]

Arranging these in ascending order, we get:
- [tex]\( \frac{3}{5} \)[/tex]
- [tex]\( \frac{7}{10} \)[/tex]
- [tex]\( \frac{12}{15} \)[/tex]
- [tex]\( \frac{21}{25} \)[/tex]
- [tex]\( \frac{18}{20} \)[/tex]

### Part 2.2
The fractions given are:
- [tex]\( \frac{7}{10} \)[/tex]
- [tex]\( \frac{12}{100} \)[/tex]
- [tex]\( \frac{65}{100} \)[/tex]
- [tex]\( \frac{5}{10} \)[/tex]
- [tex]\( \frac{23}{100} \)[/tex]

The equivalent decimal values for these fractions are:
- [tex]\( \frac{12}{100} = 0.12 \)[/tex]
- [tex]\( \frac{23}{100} = 0.23 \)[/tex]
- [tex]\( \frac{5}{10} = 0.5 \)[/tex]
- [tex]\( \frac{65}{100} = 0.65 \)[/tex]
- [tex]\( \frac{7}{10} = 0.7 \)[/tex]

Arranging these in ascending order, we get:
- [tex]\( \frac{12}{100} \)[/tex]
- [tex]\( \frac{23}{100} \)[/tex]
- [tex]\( \frac{5}{10} \)[/tex]
- [tex]\( \frac{65}{100} \)[/tex]
- [tex]\( \frac{7}{10} \)[/tex]

### Part 2.3
The fractions given are:
- [tex]\( \frac{3}{10} \)[/tex]
- [tex]\( \frac{4}{5} \)[/tex]
- [tex]\( \frac{40}{100} \)[/tex]
- [tex]\( \frac{8}{20} \)[/tex]
- [tex]\( \frac{21}{50} \)[/tex]
- [tex]\( \frac{35}{100} \)[/tex]

The equivalent decimal values for these fractions are:
- [tex]\( \frac{3}{10} = 0.3 \)[/tex]
- [tex]\( \frac{35}{100} = 0.35 \)[/tex]
- [tex]\( \frac{40}{100} = 0.4 \)[/tex] (same as [tex]\( \frac{8}{20} \)[/tex])
- [tex]\( \frac{21}{50} = 0.42 \)[/tex]
- [tex]\( \frac{4}{5} = 0.8 \)[/tex]

Arranging these in ascending order, we get:
- [tex]\( \frac{3}{10} \)[/tex]
- [tex]\( \frac{35}{100} \)[/tex]
- [tex]\( \frac{40}{100} \)[/tex]
- [tex]\( \frac{8}{20} \)[/tex]
- [tex]\( \frac{21}{50} \)[/tex]
- [tex]\( \frac{4}{5} \)[/tex]

These are the fractions arranged in ascending order for each of the given parts.