by David Cole
“It’s easy,” he said. “We just need to get our hands on the clues.”
Little did we know, getting our hands on the clues would turn out to be the easy part.
Chapter 9
After talking with Joe Ponnath, we ended up having our next Math Kids meeting at the police station. Joe’s dad was working on Saturday, and he agreed to sit down with us for a half hour to share some of the clues. I was a little surprised a police detective was willing to discuss the case with us, but Joe had explained to his dad that Stephanie and Justin had stood up for him at recess.
“What kind of information are you looking for?” Detective Ponnath asked.
“Well, we’re trying to see if maybe there is a pattern the thieves are following,” Justin explained. “If so, maybe we can use some math to figure out where they might hit next.”
Detective Ponnath chuckled. “Solving crimes is what we do for a living, Justin,” he said. “Do you really think you can find something we’ve missed?”
Justin thought about the question and then responded. “Sometimes, when I’m working on a hard math problem and get stuck, I’ll talk to Jordan about it,” Justin explained. “What I find a lot of times is that I’ll end up coming up with a solution just by talking through the problem with him.”
Detective Ponnath nodded. “Not a bad idea,” he said. “Okay, let me tell you what we’ve got. There have been seven robberies and two more attempted robberies. The latest one was three nights ago,” he started.
“Could you go through them in the order that they happened?” Justin asked. “That might help us to figure out if there is a pattern.”
As usual, he had asked just the right question.
“I can’t get into all of the details,” Detective Ponnath explained, “but most of this information is public knowledge already, so it should be okay to share.” The detective went through the burglaries in order, giving us the dates and addresses of the break-ins, as well as the items that were stolen. Justin took notes while the detective talked.
“Wow, that’s a lot of clues,” Stephanie said when Detective Ponnath had finished.
“Not really,” Detective Ponnath said. “These guys are very smart. We don’t have any witnesses. No one saw any strange cars in the neighborhood. We don’t have any physical evidence. No fingerprints, so we’re pretty sure they are wearing gloves. No shoe prints. Nothing left at the crime scene that can help us to identify the suspects.”
“But maybe there’s something here,” said Justin thoughtfully. “Maybe there’s a pattern that we’re missing.”
“Well, if you think of something, please let me know,” said the detective. “People are really scared and we need to catch these guys.”
“Why do you think it’s more than one person?” I asked.
“Great question, Jordan,” he responded. “At the last robbery, they stole a big screen television that was too big for one person to carry. That’s why we think there are at least two of them.”
We thanked the detective and headed for home. On the way, we stopped at the library and used the copier to make duplicates of Justin’s notes so we would all have them.
“I’m sure there’s some kind of pattern here,” Justin said.
“Maybe, but I don’t know how we’re going to find it if the police can’t,” I said.
“Maybe it’s like Stephanie adding up the numbers from one to one hundred,” Justin said. “Maybe we just need to think about it a little differently than the police.”
“What do you mean?” Stephanie asked.
“Well, we were trying to add the numbers one at a time because that’s the way we’ve always done it,” said Justin.
“So?” I asked.
“So, the police are used to looking for things like fingerprints and shoe prints and license plate numbers because that’s the way they’ve always done it,” Justin said. “We’ve got to look at it a different way.”
“But if the police don’t have any evidence, how are we going to catch the crooks?” Stephanie asked.
“We’ll just have to catch them in the act,” Justin said.
“How are we going to do that?” I asked.
“We’re going to think like a criminal,” Justin said with a smile. “More importantly, we’re going to think like a criminal who doesn’t want to be caught!”
Justin didn’t say any more after that. I could tell he was deep in thought as we walked home. He was looking at his notes like he thought the answer would jump right off the page if he stared long enough.
I was hoping the Math Kids were going to be able to start working on solving the burglary case right away, but Stephanie had a soccer game. Justin looked a little irritated when she said she had to go, but he didn’t say anything. Stephanie cut through the Greenfeld’s back yard to get to her house on Iowa Street. It would have been a little quicker to go through the Watsons’ yard, but the Watsons had two giant Doberman Pinschers who looked like they’d love to have a fourth grader for a snack. My sister was friends with Janet Watson and said the dogs were really pretty nice, but I didn’t want Stephanie to be the one to find out if she was wrong.
“I can’t believe she thinks soccer is more important than solving this case,” Justin said.
“She’s really good though,” I said in her defense, drawing a frown from Justin.
“So? Who cares about soccer?” he said.
I decided to keep my opinion to myself. Justin is my best friend, but he can be a little judgmental sometimes. I wondered what he would think if I said something about all of the video games he plays.
When we got to my house, I asked Justin if he wanted to come in to start looking at the clues, but he just said “Mm-hmm” and continued walking to his house.
That left just me. I poured a glass of milk and grabbed a handful of cookies from the pantry. Sitting at the kitchen table, I looked down at the information Detective Ponnath had given us, all of it written down in Justin’s neat handwriting.
1)Sept 2nd – 13 Main Street
2 TVs and jewelry
2)Sept 3rd – 29 Third Street
Money and a stereo
3)September 5th – 71 Fifth Street
Crooks stole purse off kitchen table
4)Attempted robbery on September 7th – 47 Seventh
Neighbors heard dogs barking at 9:30 pm
Police called but nothing stolen
5) September 7th – 59 Seventh Street
Money and jewelry
6)September 11th – 101 Walnut Street
Money, jewelry, and TV
7)September 13th – 149 Oak Street
Purse, wallet, laptop
8)Attempted robbery September 17th – 19 Maple
House broken into but nothing stolen
Large German shepherd in house
9)Robbery on September 19th – 3 Washington Street
Big screen TV
Seven robberies and two attempted robberies in a little more than two weeks.
As it turned out, the thieves weren’t done yet!
Chapter 10
The thieves hit again the very next night. That brought the total number of robberies up to eight. Detective Ponnath was right. These thieves were smart! Even with extra police patrols all over town, there were still no eyewitnesses to any of the robberies.
My parents were worried because it looked like the robberies were getting closer to our own house. The latest robbery was on Ohio Street, only seven streets away from ours.
My parents were planning to have a small dinner party on Saturday. They had invited Stephanie’s parents to introduce them to the neighborhood, and Justin’s parents were supposed to come too.
There was one problem though. With the latest robbery striking so close to home, my parents were thinking of cancelling their p
arty.
I called a special Monday meeting of the Math Kids. If we were going to solve the case, we needed to do it quickly!
We met at Justin’s house after school. Everyone looked very serious. This wasn’t like my sister’s seating chart. This was a real problem. Where would the robbers strike next? And when?
“What do you think, Justin?” I asked.
I could tell Justin had already put a lot of thought into the problem. His notes from the police station were marked up with circles joined by red lines and arrows. More handwritten notes had been added.
“I think there’s something there, but I haven’t figured it out yet,” he admitted. “They keep moving farther away from the river, but I’m not sure if there’s a pattern or not.”
Justin pointed to a map that he’d taped to the wall. He had large red x’s showing where every robbery or attempted robbery had taken place. The x’s showed that the robberies had started near the river and were moving farther away each time. Unfortunately, that meant they were moving closer and closer to our own houses, which Justin had put on the map too.
The streets in our town were laid out in groups of streets with similar names. The first robbery was on Main. That was followed with three robberies on what we called the number streets. There was one on Third, one on Fifth, and one on Seventh. The next three robberies were on the tree streets: Walnut, Oak, and Maple. Then there were two on the state streets: Washington and, the latest one, on Ohio. That’s how we knew the robberies were getting close to us. Stephanie lived on Iowa Street and Justin and I were on Missouri Street.
I explained the street layout to Stephanie.
“All we know is that the crooks are headed in our direction,” I said.
“I think we may know more than that,” Justin responded.
Stephanie and I looked at Justin, waiting for him to explain.
“Except for the first two robberies, they always skip at least one street in between robberies,” Justin said.
I looked at the map and saw that Justin was right. Maybe there was a pattern after all.
“It might help if we numbered the streets in the order the robberies happened,” I said. I took the marker from Justin and started to add numbers down the left side of the map, beginning with the number 1 on Main Street where the first robbery happened.
The robberies had taken place at streets numbered 1, 2, 4, 6, 10, 12, 16, 18, and 22.
“Does anyone see a pattern in those numbers?” I asked.
“Before you answer, can I ask a question?” Stephanie said.
“What is it?” I asked.
“There’s a Third street, but no First or Second. How come?” she asked.
“They renamed them to Riverfront Drive and Main Street,” I said.
“Then I think we should start the numbering with Riverfront Drive,” she said, never taking her eyes off of the map.
“Why?” I asked. “The first robbery was on Main Street.”
“Trust me. I think I might see something,” she said.
I crossed out my numbers and restarted with Riverfront Drive as number 1.
“Look at all the streets where the robberies happened,” Stephanie said excitedly.
I looked and started naming the streets, “Main, Third, Fifth—”
“No, not the names. Look at the numbers!” she exclaimed.
I started again, “Okay, we have 2, 3, 5, 7, 11—”
This time it was Justin who interrupted. “That’s it!” he grabbed the marker and started stabbing it at the numbers in excitement.
“What’s it?” I asked.
“The robberies happened on streets 2, 3, 5, 7, 11, 13, 17, 19, and 23,” he said. “Notice anything about those numbers?”
“They’re all prime!” I said. “They’re all prime numbers!”
“That’s right,” Stephanie said, her ponytail bobbing as she nodded her head with enthusiasm.
“But couldn’t that just be a coincidence?” I asked.
“Maybe,” Justin agreed.
“I don’t think so,” Stephanie said.
“Why?”
“Look at the dates of the robberies,” she said. “The robbery on Main Street, what we’re calling street 2, happened on September 2nd.”
“And the robbery on street 3 was on September 3rd!” Justin added.
We went back and checked every single one, and sure enough, every street number matched the date when the robbery happened. That couldn’t be a coincidence! The crooks had a pattern. That means we could figure out when and where the next robbery would take place.
“The last robbery was on the 23rd. The next prime number after that is 29, so if they keep following the pattern, that means the next robbery will take place on September 29th,” Justin said.
“That’s this Saturday!” I shouted.
“And that means the street will be the 29th street,” Stephanie said. She counted six streets past Ohio. Her eyes got very wide. “That’s my street!” she said.
We all looked at each other. We knew where and when the robbers were going to hit next, but what were we going to do about it?
Chapter 11
We had a hard time focusing on school for the rest of the week. Robbie and his band of merry morons continued to bother us whenever they could. Justin’s backpack spent more time on the ground than it did on its hook. We started eating lunch right next to the cafeteria monitor so we wouldn’t be bothered. We kept our eyes open for the bullies when there weren’t any adults around. To make matters worse, Mrs. Gouche continued to pile on the homework in our math group.
None of that mattered though. We needed to figure out a plan for Saturday night. But first, we needed to figure out exactly where the crooks were going to hit.
“Too bad the clues didn’t show us which specific house they were going after,” I said as Justin and I walked to the cafeteria for lunch on Wednesday.
“I think they did,” said Justin. “Well, maybe not the exact house, but at least a way to narrow it down.”
“Did you find something?” I asked.
“Yes,” Justin said. He started to explain, but our path was suddenly blocked by Robbie and Bill.
“Your little girlfriend cost us a pizza party,” Robbie growled.
“She’s not my girlfriend!” Justin shot back.
“I saw you passing notes to her today,” Bill said.
“That was math homework,” Justin said, but I knew the note was really about the burglaries because I had passed it to him.
“Wow, you really are a nerd,” Bill laughed. “Even your love notes are about math.”
“It wasn’t a love note!” Justin said. I could tell he was starting to get mad. His face was turning red and his fists were clenched by his side.
Robbie stepped forward, and Justin backed up until he was pressed against the wall. I looked around for a teacher, but there weren’t any in sight.
“You better get us our pizza party back, or instead of a date with your little girlfriend, you’ll have a date with my fist,” Robbie said as he waved his clenched fist in front of Justin’s face.
“Is there a problem here, Mr. Colson?” asked Principal Arnold as she came around the corner and saw Justin backed up against the wall.
“No problem, Principal Arnold,” Robbie replied as he backed away from Justin.
“Everything okay, Mr. Grant?” asked the principal.
Robbie gave Justin a threatening look.
“Everything’s fine, ma’am,” Justin replied.
“Then let’s get to the cafeteria,” Mrs. Arnold said. “Now, Mr. Colson!” She watched as Robbie and Bill walked down the hallway, then turned to us. “Are you sure everything is okay?” she asked Justin again.
“Yeah, everything’s fine,” Justin said.
We followed Robbie
and Bill down the hallway, while Mrs. Arnold kept a close watch on us.
Because of the argument with Robbie, we didn’t have time to discuss Justin’s ideas on the burglary until school was over. Stephanie, Justin, and I stayed in the classroom while everyone else left, except the bullies, who hung around in the hallway waiting for us until Old Mike shooed them away.
Justin was at the white board with a marker.
“What did you come up with, Justin?” I asked.
“They’re all primes!” he said excitedly.
“We already knew that,” I said. “If you start from the river, all of the streets are prime numbers.”
“No, the house addresses are all prime too,” he said. He referred to his notes as he wrote the addresses on the board.
13 Main
29 Third
71 Fifth
47 Seventh
59 Seventh
101 Walnut
149 Oak
19 Maple
3 Washington
23 Ohio
??? Iowa
Stephanie and I checked the numbers and Justin was right. All of the addresses were prime!
“That can’t be a coincidence,” Stephanie said. “It looks like when these burglars came up with a plan, they stuck with it.”
“I think they were trying to be smart by deliberately choosing a pattern that looked random,” agreed Justin. “That way the police wouldn’t be able to figure it out.”
“Now what do we do?” I asked.
“We know the day. We know the street. Now we need to figure out the house,” Justin said.
Stephanie was very quiet. She looked troubled.
“What’s wrong, Stephanie?” I asked.
“I live at 31 Iowa Street,” she said quietly.
Her house address was prime. That meant the crooks might be targeting her house for their next robbery!
“Okay, we don’t know for sure that it’s your house” I said. “We need to find out all of the houses that have prime numbers on your street.”
It didn’t take us long to find out. We just had to walk the length of her street. We only had to look at houses on one side of the street since the house numbers on the other side were all even, and we knew there were no even prime numbers except for the number 2.