Estimating by rounding to greatest place value
43 x 66
2,800
11 x 10
110
10 x 25
250
50 x 40
2000
17 x 79
1,600
12 x 12
144
21 x 13
273
62 x 40
2,480
564 x 432
240,000
13 x 59
767
25 x 20
500
23 x 90
2,070
521 x 25
15,000
27 x 46
1242
72 x 46
3312
123 x 50
6,150
916 x 45
45,000
74 x 32
2368
58 x 76
4408
324 x 60
19,440