Name: FREE Sink that Ship! Locate Benchmark Fractions on a Number Line
SKU: 65cc09a002d402190d60b173
Price: 39.99 USD
Availability: InStock

About this resource

What's inside this resource

Sink That Ship is an engaging 3-player game for practicing locating benchmark fractions on a number line. Students take turns playing the roles of Spy, Control Tower, and Commander. The Spy marks factional ship coordinates on a number line and hands it to the Control Tower. The Control Tower uses this information to give the Commander coordinates to attack. After all 3 roles are played, the Spy with the most ships remaining is the winner! This activity makes the abstract concept of plotting fractions on a number line interactive and fun. As students read and locate fractions, they develop an essential understanding of fractional parts of a whole and measurement. The differentiated "challenge mode" provides further practice opportunities. This multiplayer game is easy to implement, addictive for students, and aligns to key Common Core grade 3-5 standards on fractions.

What's included

A directions page listing the three roles - Spy, Commander, Control Tower - the materials needed, and five numbered steps from marking the ships to counting the points (page 2)
Three figures on that page showing the sequence: mark three ships, estimate where they are, count up the points (page 2)
A Tips for Teaching page covering how to make the number line concrete and which counting mistake to expect (page 3)
A Control Tower board and a matching Commander board, each with three number lines labelled A, B and C (pages 4-5)
A Challenge Mode pair of boards with denser tick marks numbered 1 to 11 across the three lines - three on A, four on B, four on C (pages 6-7)
A closing page with the author's background, a clip art credit and terms allowing reproduction in limited quantities for classroom use (page 8)

Resource types: Activities

In the classroom

Teaching tips & learning objectives

Learning objectives

Locate a benchmark fraction at the correct point on a number line
Estimate a position on a number line by distance travelled rather than by counting tick marks
Give and interpret a coordinate stated as a letter and a fraction
Compare an estimated mark against the true position by overlaying one number line on another

Teaching tips

The tips page names the mistake to expect: students count the tick marks to name the fraction, when they should be counting the spaces and thinking about how far the ship has travelled.
Drawing water along the top number line is suggested in the file itself, so that the halfway point means a ship halfway across a body of water rather than an abstract one half.
Every board is used inside a plastic sleeve with dry erase markers, so one printed set survives a whole class rotating through the three roles.
The Challenge Mode boards keep the rules identical and only tighten the tick marks, so a group that finds the first pair easy can move on without being retaught.

Skills covered

Locating benchmark fractions on a number line - the Control Tower calls a coordinate such as "A, one half" and the Commander has to find that exact point on their own line without seeing the original.
Estimating by distance - the teaching notes push students to count the spaces between tick marks and think about how far the ship has gone, rather than counting the marks themselves.
Checking a estimate against the truth - the two sleeves are laid one over the other with the edges lined up, so every mark is compared directly and the misses are visible.
Communicating a coordinate precisely - one player holds the information and another holds the marker, so the fraction has to be said clearly enough to be acted on by someone who cannot see the board.

Good to know

Questions teachers ask about this resource

How does a round actually run?

The Spy marks three one-inch ships on the Control Tower's number lines, each centred on a tick mark, and hands the sheet over. The Control Tower and the Commander sit facing each other but cannot see each other's lines. The Control Tower calls one coordinate at a time and the Commander marks an estimate for each. When all the marks are made, the Commander lays their sleeve over the Control Tower's lines with the edges aligned. Every ship not hit scores the Spy a point, then the roles rotate.

What changes in Challenge Mode?

The boards, not the rules. The second pair of number lines carries denser tick marks, numbered 1 to 11 across the three lines - three on line A, four on B and four on C - so the fractions being called sit closer together and each estimate has to be finer.

What has to be gathered before the first game?

Two plastic sheets or sleeves, two dry erase markers and two erasers, alongside the printed boards. Both the Control Tower and Commander number lines go into sleeves, which is what makes the marks wipeable and the overlay check at the end possible.