Friendly Numbers But Not
November 4, 2019 Friendly Numbers But Not! The following NT with preservice teachers included the following clusters: 999 +99 998 + 49 199 + 99 + 49 999 + 99 is 1098. Me: How did you get 1098? Explain your thinking? Katherine: I added 1 to 999 to make 1000 and took 1 from 99 to make 98. 1000+ 98 equals to 1098. All three seemed to have the same idea. 998 + 49 is 1047 Me: How did you get 1047? Explain your thinking. Chase: I separated 998 to make 990 +8 and 49 to make 40 + 9. Then I added 990 +40 which equals to 1030 and 8+9 equal 17. 1030 +17 equals 1047. Katherine: I just did like I did before but I took 2 from 49 and added it to 998. 998+2 equals 1000. 49-2 equals 47. 1000+47= 1047. 199 +99 + 49 is 347 Katherine: I took 2 from 49 and added it to 199 and 99. 199+1 is 200 and 99+1 is 100. 200 +100 equals to 300+ 47. 347 Erika: 199 +1 is 200 99 +1 is 100 49-2 is 47 200+100 +47 is 347. Disc