Math Puzzle!

Take the digits 5, 4, 3, 2 and 1, in that order. Using those digits and the four arithmetic signs — plus, minus, times and divided by — you can get 1 with the sequence 5 – 4 + 3 – 2 – 1. You can get 2 with the sequence (5 – 4 + 3 – 2) x 1.

The question is … how many numbers from 1 to 40 can you get using the digits 5, 4, 3, 2, and 1 in that order along with the four arithmetic signs?

You can group digits with parentheses, as in the example. There are no tricks to this, though. It’s a straightforward puzzle. How many numbers from 1 to 40 can you get — and, specifically, what number or numbers can you not get?

Problem of the Week Grades 1-3

```If the letter a= 1 cent, b= 2 cents, c= 3 cents, and so on up to z= 26
cents, how many \$1.00 words can you make

```
```Arrange all the integers from 1 to 9 in such a way that the numbers total
100 exactly.

Here's an example:

12 + 3 + 4 + 5 - 6 - 7 + 89 = 100

You don't have to keep the numbers in order and you can use any

How many combinations can you find?```
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Creating A Number System

The third graders have been hard at work.  After learning about Chinese Numerals, Egyptian Numbers, Roman Numerals, and a variety of base systems, the third graders are ready to create their very own number system.  They are working in pairs to develop a number system in a base other than 10.  They are designing their digits, converting between systems, and computing addition and subtraction problems!  They cannot wait to share their ideas with the class!

Number Systems

The third grade Navigate students have been busy exploring ancient number systems.  They have learned to write in Egyptian and Roman Numerals.  Both of these systems had their positives and negatives.  The students found that Egyptians had a number system in base ten so it was easier to understand, but writing out numbers proved to be time consuming.  During our discussions on Roman Numerals, the students realized that they needed to be very quick at mental math in order to figure out the values of the numbers. We discussed expanded form as well as the similarities and differences of our Hindu Arabic number system!