Mathematics 5 curriculum guide 2015 I table of contents acknowledgements

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MATHEMATICS 5 CURRICULUM GUIDE 2015
Specific Outcomes
ADDING AND SUBTRACTING DECIMALS
Suggestions for Teaching and Learning
Students will be expected to:
Number
Emphasize that when adding decimals, students must add like place 
values, i.e., tenths to tenths, hundredths to hundredths, and so on. This 
is achieved by lining up decimals when adding vertically. One cm grid 
paper or a place value chart should help students keep track of place 
value.
Provide examples of student work for class analysis such as: 
Susan added 1.469 + 11.6 and got a result of 13.069.
Ryan added the same numbers and said the answer was 1.585. 
(i) Ask students to explain why the answers are different.
(ii) Ask: Who is right? How do you know?
As students learn to add and subtract decimals, emphasize that the 
properties and techniques established for the addition and subtraction of 
whole numbers also apply to decimals. In Grade 4, students recognized 
that tenths are added to tenths, and hundredths to hundredths. This is 
also true for thousandths. Encourage students to think about what each 
digit represents. 1.234 + 0.562, for example, would be one whole, seven 
tenths, nine hundreths and six thousandths. Base ten blocks and place 
value charts will support this understanding.
In Grade 4, students used base ten blocks, number lines, regrouping, 
renaming and counting on to add and subtract decimals (to 
hundredths). They should continue to use and refine these strategies to 
add and subtract decimals to thousandths.
In Grade 4, students have represented decimals to hundredths using 
base ten materials where:
In Grade 5, the base ten materials have to extend to thousandths, and 
will, therefore, be represented as follows:
Digital versions of the base ten materials are also available online. 
5N11.4 Solve a given problem 
that involves addition and 
subtraction of decimals, limited to 
thousandths.