The sixth grade elementary school Su Jiaoban winter vacation homework mathematics thought questions. . . Master came in!
Let's talk about the eighth question first: first, divide 140g salt into two parts with a balance to get 70g, then use 2g and 7g weights to get 9g, and finally use these 9g salts and 2g weights to get 1 1g salt. The salt weighed three times adds up to only 90 grams, and the rest is 50 grams.