Grade 2 Bar Models: Finding a Part

Worked examples

Real problems from the practice worksheets, solved one step at a time.

1. Example 1

   Lisa has 52 marbles. 22 are red and the rest are blue. How many are blue?

   1. Draw one bar for all 52 of Lisa's marbles. One part is the 22 red ones; the other part is the blue ones we need to find.
   2. Whole − known part = missing part. 52 − 22: take away the tens, then the ones. 52 − 20 = 32, then 32 − 2 = 30.
   3. 30 marbles are blue.

   Answer: 30

2. Example 2

   Max has 48 pencils in all. Some are red and 13 are blue. How many pencils are red?

   1. Draw one bar for all 48 pencils. The 13 blue pencils are one part; the red pencils are the missing part.
   2. Whole − known part = missing part. 48 − 13: take away the tens, then the ones. 48 − 10 = 38, then 38 − 3 = 35.
   3. 35 pencils are red.

   Answer: 35

3. Example 3

   Emma has 69 balloons in all. Some are red and 44 are blue. How many balloons are red?

   1. Draw one bar for all 69 balloons. The 44 blue balloons are one part; the red balloons are the missing part.
   2. Whole − known part = missing part. 69 − 44: take away the tens, then the ones. 69 − 40 = 29, then 29 − 4 = 25.
   3. 25 balloons are red.

   Answer: 25