1. **Stating the problem:** We have two rectangular bar models representing fractions or division expressions. - The first bar is divided into 10 parts, 8 shaded, representing 1.8, and further divided vertically into 4 equal sections. - The second bar is also divided into 10 parts, 8 shaded, representing 1.8, but divided vertically into 5 equal sections. We want to find which division expression matches the model. 2. **Understanding the model:** - The horizontal division into 10 parts with 8 shaded means the total length is 1.8 (since 8 parts out of 10 is 0.8, but here it represents 1.8). - The vertical division into 4 or 5 equal parts means the bar is split into those many sections. 3. **Relating to division expressions:** - Dividing 1.8 by 4 means splitting the bar into 4 equal parts vertically. - Dividing 1.8 by 5 means splitting the bar into 5 equal parts vertically. 4. **Checking the options:** - $1.8 \div 3$ would mean 3 vertical sections, but the model shows 4 and 5. - $2 \div 4$ and $2 \div 5$ use 2 instead of 1.8, so they don't match the shaded length. - $1.8 \div 4$ matches the first bar (1.8 length divided into 4 parts). 5. **Conclusion:** The expression represented by the first bar model is: $$1.8 \div 4$$ The second bar model corresponds to: $$1.8 \div 5$$ Since the question asks for which expression can be represented by the model (singular), the best match is: $$1.8 \div 4$$