Posted September 1, 2011
One of the most confusing concepts to learn in 3rd grade is ROUNDING.
One of the most confusing concepts to learn in 3rd grade is ROUNDING.
I created a method to teach rounding to the 4th graders last year, that we are now using in 3rd-5th grade.
I'm certain that it is NOT how you learned to do it when you were in school. :-)
Since we will be focusing on rounding for the next week, I'd like to share the method with you (for tonight's HW!).
Problem: Round 817 to the nearest 100.
1) put a line under the number 8 (the "hundreds" place).
2) circle the number to the right of the line (the 1). That circle is the "bossy number, the "granddaddy zero."
3) look at ONLY the number in the circle. Ask "Does should it go up (use a thumb up) or should it stay the same (use the baseball "safe" sign)?
4) with 817, the number 1 in the "granddaddy circle" shows that it should stay the same ("show safe sign").
5) now rewrite the number. Start with the "Stay the same" 8, next bring down the "granddaddy zero", and then bring down the "family" little zero after it. The granddaddy zero is only followed by zeros.
Answer: 817 rounds to 800.
Problem: Round 867 to the nearest 100
1) put a line under the number 8 (the "hundreds" place).
2) circle the number to the right of the line (the 6). That circle is the "bossy number, the "granddaddy zero."
3) look at ONLY the number in the circle. Ask "Does should it go up (use a thumb up) or should it stay the same (use the baseball "safe" sign)?
4) with 867, the number 6 in the "granddaddy circle" shows that it should go UP (show "thumb up sign").
5) Put an arrow above the granddaddy zero
6) Since the granddaddy zero says that they number must go up, write a 9 above the 8.
5) Now rewrite the number. Start with the 9 you've written, next bring down the "granddaddy zero", and then bring down the "family" little zero after it. The granddaddy zero is only followed by zeros.
Answer: 867 rounds to 900.
Happy Rounding!!!!