Target Time

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Purpose

This is a level 4 number activity from the Figure It Out series. It relates to Stage 7 of the Number Framework.

A PDF of the student activity is available.

Achievement Objectives
NA4-2: Understand addition and subtraction of fractions, decimals, and integers.
Student Activity

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Specific Learning Outcomes

add and subtract decimals

Required Resource Materials

A dice

1 or more classmates

Target Game Board copymaster

FIO, Level 3, Number, Book 2, Target Time, page 16

Activity

Game

This game provides a fun context to practise the addition and subtraction of decimals. It also presents opportunities for you to explore and share addition and subtraction strategies, logical thinking in selecting a winning strategy for the game play, and place value issues with decimal numbers.
The Target game board can be photocopied (see the copymaster at the end of these notes), or the students can sketch out the boxes on draft paper for a quick copy.
This game is an ideal independent activity for pairs of students to practise decimals, but it must still be taught to the group so that they understand how to play. It can also be used as a class game.
When you use the game as a teaching activity, check that the students appreciate the place value in each of the boxes. Discuss the role of the decimal point as a device that indicates the ones column to the left. When this place is identified, the students should work out the place value of the other boxes.

blocks.
Strategies for adding or subtracting the decimals may also be part of the teaching activity. For example, if the dice produce the expression 2.5 + 3.6, the students may choose to add the ones first. This could be recorded on an open number line:

number line.
Other strategies may be to make 2.5 up to 3 and so on, for example, 2.5 + 0.5 + 3 + 0.1 = 6.1.
A third strategy could be 2.5 + 2.5 + 1.1 = 6.1.
These options show that the students are doing decimal addition at the advanced additive stage of thinking.
After the students have played the game a few times, have them discuss their strategies for winning. Ideas may include: “I put my first throw in the ones place unless it is a 5 or a 6 because these would be too high. I then have three throws to get a number in the other ones place that will make 5. The decimal bits should get me close to 6.” “I put the numbers under 4 in the ones place and the numbers greater than 3 in the tenths place.” Ask the students to test out the strategies to see
which ones work best for them.

Answers to Activity

Game
A game for adding and subtracting decimals

Attachments
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Level Four