Subtraction using Five Speckled Frogs
Grades 2-5
Objective: Students will use direct modeling to solve subtraction problems. Singing a song will help organize and the
equations and stimulate thinking to solve the problems faster.
Music Standard: Sing alone and with others.
Math Standards: Solve addition and subtraction problems with one- and two-digit numbers. Use strategies for wholenumber computation, with a focus on addition and subtraction (e.g., counting on or counting back, doubles, sums that
make 10, direct modeling with pictures or objects, numerical reasoning based on relationships).
Materials:
Place to write equations (whiteboard) and marker
Brown piece of cloth ("log") and blue piece of cloth ("pool"), about 3 yards each.
Recording of "Five Frogs," originally “Ten Little Frogs” from Spotlight on Music, Kindergarten
Process for learning song:
Teach the students the song "Five Frogs"
Cloth for "log" is on stage right and “pool” cloth is stage left
Pick 10 students to be the frogs. They hold the edge of the "log" in their hands
Play the recording of "Five Frogs"
One by one during the song, the students go over to the "pool" and hold the edge in their hands.
The log gets smaller and the pool gets bigger as the song progresses.
Alternate song activity: Sing song starting with "Five green and speckled frogs…"
Teacher holds right forearm up horizontally (log) and left hand behind it (fingers are the 5 frogs).
As frogs jump into pool, teacher moves their hand from right to left. Students see it as left to right.
Process for math operation - subtraction:
The number of frogs on the log is always the minuend (the number subtracted from) and the answer (difference).
The number of frogs jumping INTO the pool is the subtrahend (number which is subtracted)
At first, sing the song a capella (without recording) so the lyrics will fit the timing of the actions
Write subtraction problems on the board: 5 – 1 = 4, 4 – 1 = 3, etc.
Compare them to the verses of the song: 5 frogs on the log, minus 1 that jumped in = 4 left on the log
Write other subtraction problems on the board. Four example, 7 – 4 = 3 would be sung:
Seven little specked frogs, sat on a speckled log, eating some most delicious bugs
Four jumped INTO the pool, where it was nice and cool, now there were 3 green speckled frogs.
Students line up on the "log."
Write down several equations, then act them out in succession. Sample equations are used here for illustration -8 – 3 = 5. The minuend students (8, the first number) hold the log. The subtrahend students (3, the number to be
subtracted) go to the pool. The difference (answer) is the number of students left on the log (5).
9 – 3 = 6. There is a secondary problem-solving situation here. From the previous equation, only 6 frogs were left
on the log, but this new equation starts with 9 frogs. Students must decide how many additional frogs are needed
(3 more) to start. Three frogs then go into the pool, leaving 6 frogs left on the log. Students then proceed with
solving the problem.
4 – 2 = 2. This equation starts with 4 frogs, but 6 frogs were on the log from the previous equation. This means
that 2 frogs need to go back into the line and wait. Rotate students so all have turns on the “log.”
At first, sing and do the problems a capella, then try to do the problems within the timing of the recorded song.
Alternative for “log” and “pool”
Glue pieces of green (speckled) paper and blue paper back to back. While students hold up their green paper towards
the audience, touch some students on the back. While singing the words "Yum, yum," the touched people turn over their
paper to the blue side. Calculate how many are left (difference) by counting the green papers
Process for math operation – addition:
Again, the number of frogs on the log is always the first addend (number to be added to) and the answer (sum).
The number of frogs jumping OUT of the pool back onto the log is the second addend (number which is added).
The song is similar to subtraction. For example 7 + 3 = 10 would be sung:
Seven little specked frogs, sat on a speckled log, eating some most delicious bugs
Three jumped OUT OF the pool, where it was nice and cool, now there were ten green speckled frogs.
Students line up along the "pool."
Write down several equations, then act them out in succession.
The process is similar to subtraction. For example:
3 + 4 = 7. Start with 3 frogs on the log, and 4 frogs OUT OF the pool to the log, creating 7 on the log.
4 + 1 = 5. Since there were 7 left on the log from the previous equation, 3 will have to go pack into the “pool”
6 + 4 = 10. One frog jumps to the log to give 6 on the log, then 4 jump OUT OF the pool, creating 10.
At first, sing and do the problems a capella, then try to do the problems within the timing of the song.
Extension: alternate addition and subtraction
Half the students line up with the "pool" and the other half along the “log.”
Put problems on the board, alternating subtraction and addition
3 + 4 = 7. Solve the addition problem as before
7 – 2 = 5. Notice here the previous solution is the same as the minuend. No additional frogs needed.
8 + 1 = 9. Here, 3 new frogs are needed to start the equation.
Etc…
At first, sing and do the problems a capella, then try to do the problems within the timing of the song.
3 frogs (on the log), minus 1 (jumped into the pool)
equals 2 frogs (left on the log)
The following are PowerPoint slides that graphically illustrate the equations: