Poverty – i.e., financial poverty – is exacerbated by other poverties. Food poverty, including hunger and malnutrition, lead to health problems that impact a person’s potential earnings. Similarly, inadequate schooling hinders a person’s ability to find work and earn sufficient income.
The #WorldBank developed the concept of Learning Poverty to represent the inability of a 10 year old child to read and understand a simple text.
Merely being enrolled in and attending school does not guarantee meaningful gains in education. #Illiteracy rates remain high despite school participation.

53% of children in low- and middle-income countries cannot read and understand a simple story by the end of primary school. In poor countries, the level is as high as 80%

–World Bank
https://www.worldbank.org/en/topic/education/brief/what-is-learning-poverty

The Learning Poverty (LP) Indicator takes the number of students whose reading levels are insufficient (learning deprived/LD) and adds in children who do not attend school and are thus assumed to be learning deprived (schooling deprived/SD).
Also important is the learning poverty gap, that is, how far a student has to go to reach the minimum proficiency level.
Technical details on the calculations along with data can be found here: https://www.worldbank.org/en/topic/education/brief/what-is-learning-poverty.
Surprisingly, the data shows that girls have lower rates of learning poverty than boys. That means that despite many barriers to their participation in school – including reluctance of parents to pay school fees for daughters, necessity of staying home during menstruation and absences due to helping out at home – more girls are reading by age 10 than boys are.
Data by country shows which countries have high learning poverty rates. Among low and low-middle income countries, the highest rates are in Africa, led by Niger (99%), Chad (98%), Madagascar (97%) and Mauritania (95%), with other countries having rates around 80% or 90%. Afghanistan’s rate is 93% and Yemen’s 95%, while most other low- and middle-income countries in Asia and North Africa have rates ranging from 50% to 75%, as does as El Salvador (55%), not shown, and Kyrgyzstan (64%).
With the aim of achieving the UN’s Sustainable Development Goals (#SDGs) in 6 more years, countries, NGOs and #development partners need data to measure the problem so that efforts can be focused and targeted where they are most needed. The Learning Poverty indicator, developed by the World Bank several years ago, uses a more holistic approach to measuring education gaps to provide some of that needed data. 
The relevant targets for SDG #4 Quality Education are Target 4.1, ensuring all boys and girls complete free, quality primary and secondary education; Target 4.6 ensuring children and adults achieve literacy and numeracy; and 4.5 eliminating #genderdisparities in education. 
However, achievement of other targets, including Target 4.3 ensuring equal access to technical, vocational and tertiary education and Target 4.4 increasing the number of people who have relevant technical and vocational skills for employment, depends on people being able to read. 
Hence the need to reduce, if not eliminate, Learning Poverty. #Reading is the fundamental gateway that enables #learning to take place.