几道数学简算题

题目

几道数学简算题
11×22+0.22×3300+330×4.4
455×7.6+111×15.2+32.3×76
5.6×69.32+138.64×0.05+693.2×0.43
我弄不清楚,我朋友算的答案和我算的答案不一样,然后我又重新想思路算了一遍又不一样
各位谁教教我?要简算的.

答案

11×22+0.22×3300+330×4.4=11×22+22×33+33×44=22×44+33×44=44×55=121×20=2420
455×7.6+111×15.2+32.3×76=455×7.6+222×7.6+323×7.6=（455+222+323）×7.6=1000×7.6=7600
5.6×69.32+138.64×0.05+693.2×0.43=5.6×69.32+69.32×0.1+69.32+4.3=（5.6+0.1+4.3）×69.32=693.2