Add json values

{% set value_json = {"spools":[{"cost":20.0,"id":7,"name":"BLAU","profile":{"density":1.25,"diameter":1.75,"id":6,"material":"PLA","vendor":"KD Essentials"},"temp_offset":0,"used":646.0,"weight":1000.0},{"cost":26.99,"id":11,"name":"Bronze Silky green","profile":{"density":1.25,"diameter":1.75,"id":1,"material":"PLA","vendor":"Geetech"},"temp_offset":0,"used":0.0,"weight":1000.0},{"cost":25.0,"id":3,"name":"GOLD","profile":{"density":1.25,"diameter":1.75,"id":3,"material":"PLA","vendor":"Noulei"},"temp_offset":0,"used":705.0,"weight":1000.0},{"cost":20.0,"id":8,"name":"GR\u00dcN","profile":{"density":1.25,"diameter":1.75,"id":6,"material":"PLA","vendor":"KD Essentials"},"temp_offset":0,"used":681.0,"weight":1000.0},{"cost":22.94,"id":10,"name":"Rot Silk","profile":{"density":1.25,"diameter":1.75,"id":9,"material":"PLA","vendor":"Sunlu"},"temp_offset":0,"used":0.0,"weight":1000.0},{"cost":22.0,"id":4,"name":"SCHWARZ","profile":{"density":1.25,"diameter":1.75,"id":4,"material":"PLA+","vendor":"Sunlu"},"temp_offset":0,"used":796.0,"weight":1000.0},{"cost":17.99,"id":13,"name":"Schwarz","profile":{"density":1.25,"diameter":1.75,"id":8,"material":"SPLA","vendor":"Sunlu"},"temp_offset":0,"used":0.0,"weight":1000.0},{"cost":22.0,"id":2,"name":"Transparent ROT","profile":{"density":1.25,"diameter":1.75,"id":2,"material":"PETG","vendor":"BasicFil"},"temp_offset":0,"used":785.0,"weight":1000.0},{"cost":20.0,"id":9,"name":"VIOLETT Sparky Purple","profile":{"density":1.25,"diameter":1.75,"id":7,"material":"PLA","vendor":"Giantarm"},"temp_offset":0,"used":821.5133381571499,"weight":1000.0},{"cost":17.99,"id":12,"name":"Weiss","profile":{"density":1.25,"diameter":1.75,"id":8,"material":"SPLA","vendor":"Sunlu"},"temp_offset":0,"used":0.0,"weight":1000.0}]}%}

{% for x in value_json.spools %}
{{(x.weight - x.used) |round(0) }}
{% endfor %}

Result:

354

1000

295

319

1000

204

1000

215

178

1000

how can i add this values? can my where help?

regards
johann