The Great Divide

The race began with 80 bikers. After crossing the canyon, half the bikers remained in the race. Which division problem represents how many bikers were left in the race?

• 80 x 2 = 160 bikers

• 80 ÷ 2 = 40 bikers

• 80 ÷ 4 = 20 bikers

• 2 x 40 = 80 bikers

Answer explanation

The answer is 80 ÷ 2 = 40 bikers. Since half of the bikers did not cross the canyon, the original 80 bikers were split into 2, resulting in 40 bikers! Make sure to also add a label to your answer.

40 of the racers head for a boat to continue the race! A big wave comes and knocks half of the racers out of their boat. How many racers remain in the race?

• 40 ÷ 2 = 20 racers

• 2 x 20 = 40 racers

• 80 ÷ 2 = 40 racers

• 40 x 2 = 80 racers

Answer explanation

The answer is 40 ÷ 2 = 20 racers. Since 40 racers were split in half or by two, only 20 racers remain. Make sure to add a label to your answer!

Twenty racers are still in the running. While riding horses, half of the racers take the wrong path. There are now only​ ​​ (a)   left in the race.

• 5 Racers
• 10 Racers
• 15 Racers
• 20 Racers

Answer explanation

The answer is 10 Racers. Since half of the original twenty racers are out of the race, we would divide to solve. Your division problem would look like this: 20 ÷ 2 = 10 Racers.

View the students response to the scenario below:

"The remaining 10 racers hopped into a hot air balloon. Since half of the racers got caught in a storm and were unable to finish the race, you would do 10 x 2 to solve. Since 10 x 2 = 20, this means only twenty racers are left."

Is this student correct? If not, what should they have done? Select TWO choices: yes or no, and then select the correct problem.

• Yes, this student is correct.

• No, the student is incorrect.

• 10 x 2 = 20 Racers

• 10 ÷ 2 = 5 Racers

Answer explanation

This student is incorrect. Instead of dividing by two, the student multiplied which resulted in the incorrect answer. The correct problme would be 10 ÷ 2 = 5 Racers.

There are 5 racers left. Uh oh... one racer stopped running because she had a rock in her shoe! How many racers are left now?

• 5 ÷ 1 = 5 Racers

• 5 + 1 = 6 Racers

• 5 x 1 = 5 Racers

• 5 - 1 = 4 Racers

Answer explanation

The answer is 5 - 1 = 4 Racers! Since only one racer stopped the race, you would need to subtract 1 from the original 5. Make sure to add labels to your answer.

Only 4 racers remain! While racing on their bikes, two of the racers fall into a lake and stop racing. Now, there are only 2 racers left. Write an equation that represents how many racers are left:

Mathematical Equivalence

ON

Answer explanation

Since 2 racers split up from the original 4, only 2 are left. Your equation should look like this: 4 ÷ 2 = 2 racers left.

Match the division problem to the correct answer:

• 20

• 80 ÷ 2 =

• 40

• 10 ÷ 2 =

• 2

• 40 ÷ 2 =

• 10

• 4 ÷ 2 =

• 5

• 20 ÷ 2 =