从 firebase 数据库中提取特定值

如何解决从 firebase 数据库中提取特定值

鉴于来自 firebase 的这个数据库，有人能告诉我如何从 2 个数据中获得平均分数吗？ 我尝试了以下代码，但没有成功。我认为问题在于如何从数据中准确提取分值。

我试过的代码

<h3>Average total: {Object.values(learnerObjects).reduce((a,b) => a + b,0)/(learnerObjects.length || 1)}</h3> 

数据库

learners
       -MZKJfb-sDiNkSxFcqu4
       email: 
        "[e-mail]"
       firstName: 
        "Gian"
       lastName: 
        "Peppin"
       score: 
        "10"

      -MZN_V_YFt2naSReI4FA
        email: 
         "[e-mail]"
        firstName: 
         "feona"
        lastName: 
         "may"
         score: 
         "8"

{
    "-MZKJfb-sDiNkSxFcqu4": {
        "email": "[e-mail]","firstName": "Gian","lastName": "Peppin","score": "10"
    },"-MZN_V_YFt2naSReI4FA": {
        "email": "[e-mail]","firstName": "feona","lastName": "may","score": "8"
    },"-MZOBLhg1liCtmsG1M10": {
        "email": "[e-mail]","firstName": "teo","lastName": "mammuccari","score": "7"
    },"-MZOBWPymXWdqjknKpfu": {
        "email": "[e-mail]","firstName": "mirko","lastName": "de luca","score": "5"
    },"-MZR2K_Cwkcqbz-UFlsN": {
        "email": "[e-mail]","firstName": "Salvatore","lastName": "De Gennaro","-MZR7AQggg222CYFFII_": {
        "email": "[e-mail]","firstName": "Nikhil","lastName": "Piparia","score": "6"
    }
}