10,658 rounded to the nearest hundred is 10,700

692 rounded to the nearest tens is 690

45,231 rounded to the nearest hundred is 45,200

45,231 rounded to the nearest ten is 45,230

math lesson 17

68,740 rounded to the nearest ten thousand is 70,000

7,255 rounded to the nearest thousand is 7,000

789,467 rounded to the nearest hundred thousand is 800,000

555,555 rounded to the nearest thousand is 556,000

math lesson 18

1,892 estimated is 1,890

68 estimated is 70

1,890+70=1,960

489 estimated is 490

387 estimated is 390

490+390=880

28 estimated is 30

339 estimated is 340

30+340=370

987 estimated is 990

123 estimated is 120

990+120=1,110

math lesson 19

239 estimated by tens is 240

176 estimated by tens is 180

240-180=60

972 estimated by tens is 970

157 estimated by tens is 160

22 estimated by tens is 20

970-160-20=780

1,399 estimated by thousands is 1,000

1,202 estimated by thousands is 1,000

1,000-1,000=0

14,785 estimated by thousands is 15,000

3,679 estimated by thousands is 4,000

15,000-4,000=11,000

math lesson 21

231×2=462

132×3=396

221×4=884

303×2=606

444×2=888

1332×3=3996

math lesson 22

5142×5=25715

4184×6=25104

809×11=8899

43×32=1376

1304×212=248648

3110×3112=9678320