This problem solving activity has an algebra focus.
Ben has a box with a number in it that is greater than 7.
Moana has a box with a number in it that is less than 9.
Tom has a box with a number in it that is greater than 5.
They all have the same number. What is it?
Equations (statements of equality) that use the symbol = are often familiar to students. Statements of inequality that use the symbols < (less than) and > (greater than) may be less familiar.
This problem explores statements of inequality and the ways these are recorded using symbols. The problem itself may not be numerically challenging for your students, however understanding relationships and expressions between numbers is an important aspect of algebra. The number line representations of the inequality expressions shown in the solution make the relationships evident.
Ben has a box with a number in it that is greater than 7.
Moana has a box with a number in it that is less than 9.
Tom has a box with a number in it that is greater than 5.
They all have the same number. What is it?
Make up your own 3 clue problems for others to solve. The solution to these will be dependent on the problems posed. Look for students to use the < > symbols correctly.
Students should recognise the following facts: Ben's number can be any number that is greater than 7, Moana's number must be less than 9, and Tom's number number must be greater than 5. Present each student's statement on a number line:
Comparing two lines, we notice that only 6 is on both Tom's line and Moana's line.
The number lines clearly show 8 is the number that satisfies all of the inequalities. It s greater than 5 and 7, but less than 9.
Printed from https://meaningfulmaths.nt.edu.au/mmws/nz/resource/figure at 8:56pm on the 26th February 2024