小学数学二年级加减法估算课件24课件维语

1、?峘峘 ?ral?f ?riar?i?婰 ?rial? 2-2-?llal 1- 1- ?ala 7- 7- ?ri?118 29 23 44 52 6830 20 40 50 7020a峘f ?lla ?1?1i ?峘lrlf a卨arral ?rf ?aa?l2?ar?婰 峘l ?rala?峘 ?a9al ?i?rf 1- r?ir180 rr? 2- r?ir340 rr?3- r?ir192 rr?4- r?ir219 rr?al ?ra ?rariaf峘l a卨a峘?lf ?allal峘 3-4- 3-4- r?ir ?f婰re r?ra rr? a?峘 ?aa9al33-4- r?

2、ir ?rra婰裔r? r?ra rr? a?峘 ?aa9al192 + 219 400410420?ar?婰 峘l ?rala?峘 ?a9al ?i?rf 1- r?ir180 rr? 2- r?ir340 rr?3- r?ir192 rr?4- r?ir219 rr?4192 + 219 400410420500 rr? ?ra9il? ?a?aa? ?峘l峘峘? ?rra婰裔r? rrrl r?ra rr? ?araa9al ?ala aa?rrrl ?a? ?峘l峘峘?ar?婰 峘l ?rala?峘 ?a9al ?i?rf 1- r?ir180 rr? 2- r?ir340 rr?3-

3、 r?ir192 rr?4- r?ir219 rr?5?rr婰 400 ?rf1l ?峘i aa? ?峘 ?af ?a裔 ?ralarr aaal?a?l ?峘婰r?al 245 + 187 = 432( (?rf1l)?r1?: ?rf1l 400 432 ?rf1l ?峘?a 峘lr婰?rl.245 245 ?rf1l187?rf1l 6?rr婰 400 ?rf1l ?峘i aa? ?峘 ?af ?a裔 ?ralarr aaal?a?l ?峘婰r?al 245 + 187 ?r1?: ?rf1l 40 400 4?rf1l ?峘?a 峘lr婰?rl.440 （?rf1l） 250 250

4、190 190 245 245 ?rf1l187?rf1l 7?arf ?rl?aai ?la?f ?r?婰 峘a?ral.8.1.1?f婰re 237 237?r? ?rra婰裔r? rrrl ?r?r? ?1a? ?a9a婰il?. . 100142 143 237 - 142237 - 142 100 （?r?） 240 240 140 140 _9ala峘?ilfa卨?alli a9rrai峘alaf a9ra卨a峘?ilf ?ra卨aa _ ?rf1l ?arf2. ?a?ael? r?arrlai? ?rai峘alaf ?ala?620 ?rf1l ?illa? ?ala?147 ?rf1l.470 620 - 147 470 （元）（元） 620 150 10583 + 41 7 7 18 + 1 79 3.?riar?i?婰 ?rial?631