© Hamilton Trust Keeping Up Term 3 Week 2 Day 3

Objective:• Use written column addition to add

numbers with one or two decimal places .

Written Addition – Objectives

© Hamilton Trust Keeping Up Term 3 Week 2 Day 3

Written Addition – Direct TeachingStep 1: Write the numbers in columns, one above the other. 10s 1s . 0.1s

2 6 . 8 + 1 5 . 7

.

Step 2: Add the tenths column. Write the extra 1 in the 1s column. 10s 1s . 0.1s

2 6 . 8 + 1 5 . 7 1 . 5

Hints: Leave a space before drawing the lines. Write the decimal point in the answer so you don’t forget it later.

© Hamilton Trust Keeping Up Term 3 Week 2 Day 3

Written Addition – Direct TeachingStep 3: Add the 1s, including the extra one. Write the extra ten in the 10s column. 10s 1s . 0.1s

2 6 . 8 + 1 5 . 7 1 1 2 . 5

Step 4: Add the tens column.

10s 1s . 0.1s

2 6 . 8 + 1 5 . 7 1 1 4 2 . 5

© Hamilton Trust Keeping Up Term 3 Week 2 Day 3

Written Addition – Student ActivityMake a pair of three-digit numbers, each with one decimal place, and add them together.

97532108

46

Use the same cards to make the smallest total that

you can and the largest possible total…

© Hamilton Trust Keeping Up Term 3 Week 2 Day 3

Written Addition – Direct TeachingAdding pairs of four digit

numbers with two decimal places:

10s 1s . 0.1s 0.01s

2 6 . 8 3+ 1 5 . 7 8 1 1 1 4 2 . 6 1

Discuss with a partner the steps shown for adding pairs of four digit numbers with two decimal places.

Hint: Leave a space before drawing the lines. That way, there is somewhere to write the extra tenths, 1s and 10s.

© Hamilton Trust Keeping Up Term 3 Week 2 Day 3

Written Addition – Direct TeachingAdding pairs of numbers with different numbers of decimal places:

2 6 . 8 + 1 5 . 7 8 Are you happy that this

calculation has been set out correctly?

© Hamilton Trust Keeping Up Term 3 Week 2 Day 3

Written Addition – Individual Practice

37.5 + 23.8 58.2 + 42.9 27.58 + 35.6

Choose a challenge and solve all three questions to be a decimal dude or diva!

Watch out… Convert numbers to decimals if necessary!

67.5 + 43.8 58.72 + 42.69 74.58 + 85.6

74.58 + 85.6 98.49 + 71.68 4.76m + 565cm

1.27km + 850m 0.18kg + 2650g 1580mL + 2.09L