Learn about bar models at NCTM? Submit your bar model using your iPad as a sketch tool. To try, click the button to launch…
Apr
13
related sites
…research Singapore math collections online
Apr
13
by kellitrainer
Learn about bar models at NCTM? Submit your bar model using your iPad as a sketch tool. To try, click the button to launch…
…research Singapore math collections online
8 comments
Cheryl Michels says:
April 14, 2011 at 3:23 pm (UTC -7)
I got the answer of 19 through guess and check, but I am having a hard time solving this with the bar method. We are a first year school with Singapore and more of these challenges with answers will help us (who were definitely not brought up doing this math) to be able to communicate our learning to our students.
kellitrainer says:
April 15, 2011 at 1:12 pm (UTC -7)
Cheryl….you are so right. It takes a few steps…to solve a problem the way our brain works…then try the bar model…but think out loud. Students need have that metacognition modeled so they realize it’s a process and not always the same process…right? Appreciate the request for more challenges….on my to-do-list!
Cheryl Michels says:
April 14, 2011 at 3:25 pm (UTC -7)
Never mind – Duh I see it now. 133-57 = 76/4 = 19
Rose says:
April 14, 2011 at 4:28 pm (UTC -7)
133-x = 3(57-x) That’s how I figured it out
x=19
Kathleen Jalalpour says:
April 15, 2011 at 6:46 am (UTC -7)
Rainer |______|______|______|_t_| } 133
Joel |______|_t_| } 57
133 – 57 = 76 for 2 units (Rainers 3 units + t , minus Joel’s 1 unit +t, leaves 2 units on Rainer’s bar)
76 / 2 = 38 for one unit.
57 – 38 = 19 (Joel’s bar is 1 unit (=38) and 1 t shirt. Subtract 38 and you have the t-shirt).
The t-shirt costs $19.
kellitrainer says:
April 15, 2011 at 1:07 pm (UTC -7)
Never seen that before…bar model within comment…innovative!
Daniel (from Clinton Elementary) says:
April 15, 2011 at 6:47 am (UTC -7)
(57-x)*3=(133-x)
multiply 3
171-3x=133-x
add x
171-2x=133
subtract 171
-2x=-38
divide -2
x=19
Cynthia McKenzie says:
April 21, 2011 at 6:03 pm (UTC -7)
R $19 $38 $38 $38
J $19 $38
$133 + $57 = $190 (total amount they both started off with)
$190/5 = $38 (cost of both t-shirts)
$38/2 = $19 (cost of each t-shirt)