# This is a math lesson on estimation using calculators

Subject:

Math

2, 3

Jenny Bay

Topic:

calculator use. estimation strategies.
subtracting 3-digit

2 – 3 (level of difficulty

Name of Activity: Tic – Tac – Toe:

A Number Game

Materials Needed:

calculators

&
worksheets (one of each for each pair of

students)

Description of Activity

Divide all students into pairs. Have the students choose a Player
X and a Player 0. Have the students decide which of the players
will go first. (For example, Player X goes first). Player X chooses
a square from the worksheet (see attached) and estimates the answer
to the problem in that square. Player X writes his/her answer
on the sheet and Player O checks the estimate on the calculator.
If the estimate is within "25" of the correct answer,
Player X places an X in his/her square and it is Player O’s turn
to estimate. If the answer is not within "25", Player
O places an O in the square and takes his/her turn choosing a
square and estimating. The players continue taking turns estimating
and checking one another’s answers. The first player to get three
Xs or Os in a row (horizontally, diagonally, vertically) wins!

The activity can be modified to include "easier" or
"harder" problems. The activity can be modified to include
a range greater or less than 25.