Transcript Singapore Math

Singapore Math
Using the Bar Model Approach
A couple of word problems…
• Easy to solve
– A man sold 230 balloons at a fun fair in the
morning. He sold another 86 balloons in the
evening. How many balloons did sell in all?
• Not-So-Easy to solve
– Lauren spent 20 percent of her money on a dress.
She spend 2/5 of the remainder on a book. She
had $72 left. How much money did she have at
first?
In Singapore…
• Those two word problems would be solved
using the same bar model technique.
– First encounter this technique in 3rd grade
– In 4th and 5th grade, technique applied to more
difficult, multi-step problems
– By 6th grade, technique is being used to solve
difficult problems
The Bar Modeling
Technique…
• Teaches students how represent problems
symbolically - algebraic reasoning
• Can be applied to many complex problems
involving comparisons, part-whole
calculations, ratios, proportions and rates of
change
• Communicates what the learner already
knows and shows them how to use that
knowledge to solve the problem
• Sets students up to easily transition into
Algebra
Part-whole model
Daniel and Peter have 450 marbles.
Daniel has 248 marbles.
How many marbles does Peter have?
450
248
?
Gives a visual model and helps student interpret language.
Comparison Model
Daniel has 248 marbles.
Peter has 202 marbles.
Who has more marbles? How much more?
248
202
?
Compares two different quantities.
Works for problems that are solved by subtraction.
Two Step Model
Bracket is used to join the bars.
Mary had 120 more beads than Jill. Jill had 68 beads.
Step 1: How many beads did Mary have?
Step 2: How many beads did the two girls have altogether?
?
?
68
120
Practice Problem
Sam is driving to visit his sister. He drove
40% of the entire trip on Monday.
Tuesday he drove 7/8 of the remainder of
the trip. Sam has 60 miles left to drive on
Wednesday before he arrives. How many
miles is Sam’s trip.
Practice Problem
Bob spent 40% of his allowance on
books. He spends 1/3 of what's left on a
shirt. He has $100 left. How much did
he get for his allowance?