Math in Action 2014-2015
Welcome to the first math challenge of 2014-2015. We invite you to participate in all 15 math challenges
planned for the school year. A schedule of the challenges and due dates are listed online at the Math in
Action website (www.mathinaction.org).
Students in Kindergarten through 5th grade are invited to take part in solving these
fun math problems. Parents and siblings are encouraged to discuss these math
problems with students. Students who submit qualified answers to at least 12 math
challenges will be honored at the award assembly in June 2015.
Notes to Parents
There are seven strategies that will be covered in 2014-2015 math challenges: work backward, draw a
picture/diagram/model, look for patterns, make an organized list or a table, act out the problem, guess and
check, and use logical reasoning. There is an explanation and examples for each strategy on the website.
Feel free to check them out.
If you are new to our format of math challenge, we often group problems
so students focus on one or two strategies. For example, math problems in
our first challenge can be solved using logical reasoning and/or drawing a
picture/diagram/model. However, since students learn in different ways,
some students may wish to use a strategy other than the one(s) suggested
in the math challenge. If students come up with more than one strategy, encourage them to use the best
method for them. We want to equip them with these strategies but we also want them to be flexible in
applying them. As they become more skilled, they may combine two or more strategies to effectively solve
problems.
If students get stuck on a problem, try not to offer the solution right away. Start a discussion
about strategies and reread the problem together. If students enjoy math, try to challenge
them to solve more problems than required.
*****
Our first Math Challenge is about digits and numbers. Digits and numbers are like letters and words. In the
vocabulary world we use letters to write words. In the number world we use digits to write numbers.
Numbers are used to express amount, total or measurement. We also use them for labels (telephone
numbers), for ordering (serial numbers), and for codes. The following are definitions of words that may help
you solve this first Math Challenge.
Vocabulary:
Consecutive Numbers - numbers which follow each other in order, without gaps, from smallest to largest.
Even number - numbers ending with 0, 2, 4, 6 or 8. Also, any integer that can be divided exactly by 2.
Odd number - numbers ending with 1, 3, 5, 7 or 9. Also, any integer that cannot be divided exactly by 2.
Sum - the result of adding two or more numbers.
Product - the result of multiplying two or more numbers.
Prime Numbers – numbers only evenly divisible by 1 and itself.
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Math in Action 2014-2015
First Name: ____________________
Last Name: ____________________
Grade: _______ Teacher: ________________
Your solutions are due on Thursday, October 9 (no later than 3 p.m.). Submit your solutions to your teacher or to
your school office by the due date.
Kinder & First Grade: Solve at least 4 problems correctly.
Second & Third Grade: Solve at least 9 problems correctly.
Fourth & Fifth Grade: Solve at least 14 problems correctly.
Digits and Secret Numbers
1.
My secret number is a two-digit number. The first digit is the number of your eyes, and
the second digit is the number of fingers on your right hand.
Answer:
2.
How many even digits are in the number 13,056?
_____________
Answer:
3.
What is the sum of odd digits in the number 55,012?
_____________
Answer:
4.
My secret number is the sum of the number of fingers on my left hand plus the number
of all of my toes.
5.
Sophia’s secret number is a three-digit number. The digits are in counting order. If
you add the digits, the sum is 12. What is Sophia’s secret number?
_____________
Answer:
_____________
Answer:
_____________
6.
The sum of two consecutive numbers is 13, what are the numbers?
7.
Guess Rachel’s secret number. The number is greater than the number of days in
November but it is less than the number of inches in six feet. It is an even number, and if
you count by 10s, you say the number. The sum of its digits is equal to the number of days
in a week.
8.
Using each of the digits 1, 2, 3, 4, 5, 6, 7, 8, and 9 only once, fill in the rectangles to make
three mathematical sentences.
+
=
-
=
×
=
Answer:
Answer:
_____________
Answer:
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Math in Action 2014-2015
9.
Guess Anita’s secret number. The number is greater than the number of pennies in a
quarter. It’s less than the number of pennies in 5 dimes. It is an odd number. If you count
by 5s, you say the number. The sum of the digits is 8. What is Anita’s secret number?
10.
Each letter below represents a different digit. Can you decipher the
following so that it makes a correct multiplication problem?
Answer:
_____________
Answer:
___________
BA x 7 = HAA
11.
Can you arrange these five digits 1, 2, 3, 4, 5, so that the first two digits multiplied by the
middle digit will produce the last two digits?
Answer:
12.
13.
×
=
You take a two-digit number, reverse its digits to make a second two-digit number,
and add these two numbers together. If the answer is 121, what are all the possible
two-digit numbers?
Maria’s secret number is a prime number that is larger than 20 but less than 50.
The sum of its digits is 10. What is Maria’s secret number?
Answer:
___________
Answer:
___________
14.
15.
16.
Find Aditi’s number. The hundred’s digit is an even number between 5 and 8. The ten’s
digit is 3 less than the hundred’s digit. The one’s digit is the hundred’s digit plus the ten’s
digits.
Answer:
In the multiplication problems below, A, B, C, and D represent different digits. ABC
is a three-digit number, and * means multiplication. What three-digit number does
ABC represent? What number does D represent?
ABC
* D
1673
Answer:
The digit 3 is written at the right of a certain two-digit number thus forming a three-digit
number. The new number is 372 more than the original two digit-number. What was the
original two-digit number?
Answer:
___________
___________
___________
Math Challenge 2 will be available online October 17, 2014 at www.mathinaction.org.
Math Kangaroo and Fall NLMC registration is now open. Links are available at www.mathinaction.org.
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