Tính toán với số thập phân

Home Lớp 6 Toán lớp 6 - Sách kết nối tri thức Bài 29: Tính toán với số thập phânBài tập cơ bản

{"common":{"save":0,"post_id":"4605","level":1,"total":10,"point":10,"point_extra":0},"segment":[{"id":"6794","post_id":"4605","mon_id":"1158113","chapter_id":"1158126","question":"N\u1ed1i phép tính v\u1edbi k\u1ebft qu\u1ea3 \u0111úng<\/p>","options":[["(-3,9) + (-2,85)","(-4,65) + 2,3","(-5,6) + 9,25"],["-2,35","3,65","-6,75"],["-6,75","-2,35","3,65"]],"correct":[1,2,0],"level":"1","hint":"- Mu\u1ed1n c\u1ed9ng hai s\u1ed1 th\u1eadp phân âm, ta c\u1ed9ng hai s\u1ed1 \u0111\u1ed1i c\u1ee7a chúng r\u1ed3i thêm d\u1ea5u tr\u1eeb tr\u01b0\u1edbc k\u1ebft qu\u1ea3.<\/p>- Mu\u1ed1n c\u1ed9ng hai s\u1ed1 th\u1eadp phân trái d\u1ea5u<\/strong> ta làm nh\u01b0 sau:<\/p>    + L\u1ea5y s\u1ed1 d\u01b0\u01a1ng tr\u1eeb cho s\u1ed1 \u0111\u1ed1i c\u1ee7a s\u1ed1 âm<\/strong> n\u1ebfu s\u1ed1 d\u01b0\u01a1ng l\u1edbn h\u01a1n ho\u1eb7c b\u1eb1ng s\u1ed1 \u0111\u1ed1i c\u1ee7a s\u1ed1 âm<\/strong>.<\/p>    + L\u1ea5y s\u1ed1 \u0111\u1ed1i c\u1ee7a s\u1ed1 âm tr\u1eeb cho s\u1ed1 d\u01b0\u01a1ng<\/strong> và \u0111\u1eb7t d\u1ea5u tr\u1eeb tr\u01b0\u1edbc k\u1ebft qu\u1ea3<\/strong> n\u1ebfu s\u1ed1 d\u01b0\u01a1ng nh\u1ecf h\u01a1n s\u1ed1 \u0111\u1ed1i c\u1ee7a s\u1ed1 âm<\/strong> <\/p>","answer":"(-3,9) + (-2,85) = -(3,9 + 2,85) = -6,75    (vì 3,9 > 0 và 2,85 > 0)<\/p>(-4,65) + 2,3 = -(4,65 - 2,3) = -2,35         (vì 4,65 > 2,3)<\/p>(-5,6) + 9,25 = 9,25 - 5,6 = 3,65              (vì 9,25 > 5,6)<\/p>\u0110áp án \u0111úng c\u1ea7n n\u1ed1i là <\/p>(-3,9) + (-2,85) = -6,75<\/strong><\/span><\/p>(-4,65) + 2,3    = -2,35<\/strong><\/span><\/p>(-5,6) + 9,25    = 3,65<\/strong><\/span><\/p>","type":"matching","extra_type":"mat_txt","time":"0","user_id":"131","test":"3","date":"2021-08-29 01:07:41"},{"id":"6796","post_id":"4605","mon_id":"1158113","chapter_id":"1158126","question":"Phép tính nào cho k\u1ebft qu\u1ea3 nào \u0111úng<\/strong> ?<\/p>","options":["A.<\/strong> (-2,586) + 54,253 = 51,667","B.<\/strong> 56,21 + (-100,85) = 44,64","C.<\/strong> (-125,33) + (-56,365) = 181,695"],"correct":"1","level":"1","hint":"- Mu\u1ed1n c\u1ed9ng hai s\u1ed1 th\u1eadp phân âm, ta c\u1ed9ng hai s\u1ed1 \u0111\u1ed1i c\u1ee7a chúng r\u1ed3i thêm d\u1ea5u tr\u1eeb tr\u01b0\u1edbc k\u1ebft qu\u1ea3.<\/p>- Mu\u1ed1n c\u1ed9ng hai s\u1ed1 th\u1eadp phân trái d\u1ea5u<\/strong> ta làm nh\u01b0 sau:<\/p>    + L\u1ea5y s\u1ed1 d\u01b0\u01a1ng tr\u1eeb cho s\u1ed1 \u0111\u1ed1i c\u1ee7a s\u1ed1 âm<\/strong> n\u1ebfu s\u1ed1 d\u01b0\u01a1ng l\u1edbn h\u01a1n ho\u1eb7c b\u1eb1ng s\u1ed1 \u0111\u1ed1i c\u1ee7a s\u1ed1 âm<\/strong>.<\/p>    + L\u1ea5y s\u1ed1 \u0111\u1ed1i c\u1ee7a s\u1ed1 âm tr\u1eeb cho s\u1ed1 d\u01b0\u01a1ng<\/strong> và \u0111\u1eb7t d\u1ea5u tr\u1eeb tr\u01b0\u1edbc k\u1ebft qu\u1ea3<\/strong> n\u1ebfu s\u1ed1 d\u01b0\u01a1ng nh\u1ecf h\u01a1n s\u1ed1 \u0111\u1ed1i c\u1ee7a s\u1ed1 âm.<\/strong><\/p>","answer":"A.<\/strong> (-2,586) + 54,253 = 51,667<\/span>      (\u0111úng<\/span> vì (-2,586) + 54,253 = 54,253 - 2,586 = 51,667)<\/p>B.<\/strong> 56,21 + (-100,85) = 44,64 (sai<\/span> vì 56,21 + (-100,853) = -(100,853 - 56,21) = -44,64)<\/p>C. <\/strong>(-125,33) + (-56,365) = 181,695 (sai<\/span> vì (-125,33) + (-56,365) = -(125,33 + 56,365) = -181,695)<\/p>\u0110áp án \u0111úng là   A.    (-2,586) + 54,253 = 51,667<\/span><\/strong><\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"131","test":"3","date":"2021-08-29 01:14:32","option_type":"txt","len":2},{"id":"6797","post_id":"4605","mon_id":"1158113","chapter_id":"1158126","question":"Phép tính cho k\u1ebft qu\u1ea3 nào sai <\/strong>?<\/p>","options":["A.<\/strong> 25,64 - 39,562 = -13,922","B.<\/strong> 125,349 - (-62,5) = 187,849","C. <\/strong> 78,52 - 25,24 = -53,28"],"correct":"3","level":"1","hint":"Cho a và b là hai s\u1ed1 th\u1eadp phân thì   a - b = a + (-b)<\/strong><\/p>","answer":"A.<\/strong>  25,64 - 39,562 = -13,922      (\u0111úng vì 25,64 - 39,562 = 25,64 + (-39,562) = -(39,562 + 25,64) = -13,922)<\/p>B.<\/strong>  125,349 - (-62,5) = 187,849  (\u0111úng vì 125,349 - (-62,5) = 125,349 + 62,5 = 187,849)<\/p>C. <\/strong> 78,52 - 25,24 = -53,28   <\/span>        (sai <\/span>vì 78,52 - 25,24 = 53,28)<\/p>Vì \u0111\u1ec1 yêu c\u1ea7u ch\u1ecdn phép tính sai<\/strong> nên \u0111áp án \u0111úng là  C.  78,52 - 25,24 = -53,28 .<\/span><\/strong><\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"131","test":"3","date":"2021-08-29 01:32:26","option_type":"txt","len":2}]}