How I Learned Geography by Uri Shulevitz

From chapters.ca:
Having fled from war in their troubled homeland, a boy and his family are living in poverty in a strange country. Food is scarce, so when the boy's father brings home a map instead of bread for supper, at first the boy is furious. But when the map is hung on the wall, it floods their cheerless room with colour. As the boy studies its every detail, he is transported to exotic places without ever leaving the room, and he eventually comes to realize that the map feeds him in a way that bread never could.