CALCULATING THE AGE OF A STUDENT FOR ASSESSMENT

NATIONAL ASSOCIATION OF SPECIAL EDUCATION

TEACHERS

CALCULATION OF AGE Any time you test a

child, perhaps the most important piece of information you must obtain is the child’s age at the time of testing (known as Chronological Age).

Miscalculating a child’s chronological age will result in faulty interpretations and scores.

Therefore, it is necessary to take your time and be sure of a child’s chronological age when determining how old he or she is at the time of testing

Chronological Age is often abbreviated as C.A.

Why Not Just Ask Children Their Ages?

The answer is threefold:

1. Many children do not know when they were born or how old they are

2. Children think they know their Date of Birth but are incorrect.

3. Ages (when doing an evaluation) are broken down into Years, Months, and Days, something that children would not normally know.

Years-Months-Days

For example, you may calculate that a child has a chronological age of 7-9-13.

This means that the child is 7 years, 9 months, and 13 days old.

If you determine that a child is 11-5-17, this represents a child who is 11 years, 5 months, and 17 days old.

Calculation of Age YEAR MONTH

DAYS Date of Test __________ __________ __________

Date of Birth __________ __________ __________

Chronological Age __________ __________ __________

To calculate Chronological Age, the first step is simply to fill in the appropriate lines for Date of Test and Date of Birth.

A child who was tested on November 25, 1999, and who was born on July 9, 1985, would have the following box:

Year MonthDays

Date of Test 1999 11 25

Date of Birth 1985   7  9

Chronological Age ___ ___ ___

In the box, Date of Test of November 25, 1999, is represented by 1999-11-25,

In the box, Date of Birth of July 9, 1985, is represented by 1985-7-9.

Right to Left Subtraction Rule

Important Point: Always start the subtraction process from RIGHT to LEFT (i.e., subtract the Days, then the Months, and lastly, the Years).

You must always follow this procedure!

Calculation of AgeYEAR MONTH DAYS

Date of Test 1999 11 25

Date of Birth 1985   7  9

Chronological Age 14    4 16

This child was 14-4-16 at the time of testing 14 years, 4 months, and 16 days old.

Rounding Up Ages On many tests (or in educational reports and IEPs), the

age may be rounded up/down to Years and Months.

General Rule (see manual for specifics): If the number of days is greater than 15, the age is rounded up.

C.A. of 10-7-24 would become 10-8

If the number of days is less than or equal to 15, it remains the same.

C.A. of 8-6-2 would become 8-6

Date of Test DAYS is Less Than Date of Birth DAYS.

Now, suppose you have a child whose Date of Test DAYS is less than his or her Date of Birth DAYS.

Date of Test DAYS is Less Than Date of Birth DAYS.

Suppose you have a child who was tested on August 11, 2005.

He was born on May 23, 1995.

YEAR MONTH DAYS Date of Test 2005 8 11

Date of Birth 1995 5 23 Chronological Age ___________ __________ __________

RULE for When Date of Test DAYS is Less Than the Date of Birth DAYS

Rule: Subtract 1 from the Date of Test MONTHS and add 30 to the Date of Test DAYS

You are simply replacing 1 month with 30 days.

Date of Test DAYS is Less Than Date of Birth DAYS.

You cannot subtract 23 from 11, so simply subtract 1 from the Date of Test MONTHS (8 – 1 = 7) and add 30 to Date of Test DAYS (11 + 30 = 41).

YEAR MONTH DAYS Date of Test 2005 7 (8-1) 41 (11+ 30)

Date of Birth 1995 5 23

Chronological Age ______ _______ _______

Date of Test DAYS is Less Than Date of Birth DAYS.

Now, simply subtract as you normally would:

YEAR MONTH DAYS Date of Test 2005 7 41

Date of Birth 1995 5 23

Chronological Age 10 2 18

This child is 10-2-18. (For assessment purposes, the child’s age probably would be recorded as 10-3.)

Date of Test MONTHS is Less Than the Date of Birth MONTHS.

Now, suppose the Date of Test MONTHS is less than the Date of Birth MONTHS.

Date of Test MONTHS is Less Than the Date of Birth MONTHS.

Suppose a child’s Date of Birth is November 4, 2000.

His Date of Testing was on April 15, 2005.

Calculate his Chronological Age at the time of testing.

Date of Test MONTHS is Less Than the Date of Birth MONTHS.

YEAR MONTH DAYS Date of Test 2005   4 15

Date of Birth 2000 11   4

Chronological Age __________ __________ 11 You cannot subtract 11 MONTHS from 4

MONTHS.

RULE for When Date of Test MONTHS is Less Than the Date of Birth MONTHS.

RULE: When Date of Test MONTHS is Less Than the Date of Birth MONTHS, subtract 1 from the Date of Test YEARS and add 12 to the Date of Test MONTHS

You are replacing 1 year with 12 months.

Date of Test MONTHS is Less Than the Date of Birth MONTHS. Therefore, subtract 1 from the Date of Test

YEARS (2005 – 1 = 2004) and add 12 to the Date of Test MONTHS (4 + 12 = 16).

YEAR MONTH DAYS Date of Test 2004 (2005-1) 16 (4 + 12) 15

Subtract as you normally would. Now, the box looks like this:

Date of Test MONTHS is Less Than the Date of Birth MONTHS.

YEAR MONTH DAYS

Date of Test 2004 (2005-1) 16 (4 + 12) 15

Date of Birth 2000 11   4

Chronological Age ______ _____ 11

Date of Test MONTHS is Less Than the Date of Birth MONTHS.

YEAR MONTH DAYS Date of Test 2004   16 15

Date of Birth 2000 11   4

Chronological Age 4 5 11

This child was 4-5-11 when tested.

The Ultimate Age Calculation Problem

If you can do this problem, then you should be able to do any calculation of age.

Try this one:

The Ultimate Age Calculation Problem

A child is tested on March 14, 2005.

He was born on December 29, 1993.

What was his age at the time of testing?

The Ultimate Age Calculation Problem

YEAR MONTH DAYS

Date of Test 2005   3 14

Date of Birth 1993 12   29

Chronological Age _____ _____ ____

The Ultimate Age Calculation Problem

YEAR MONTH DAYS

Date of Test 2005   2 44

Date of Birth 1993 12   29

Chronological Age _____ _____ 15

The Ultimate Age Calculation Problem

YEAR MONTH DAYS

Date of Test 2004   14 44

Date of Birth 1993 12   29

Chronological Age _____ 2 15

The Ultimate Age Calculation Problem

YEAR MONTH DAYS Date of Test 2000   3 14

Date of Birth 1988 12   29

Chronological Age 11 2 15

This child was 11-2-15 when tested.

Practice Problem—Calculate Your

Chronological Age

YEAR MONTH DAYS Date of Test

Date of Birth

Chronological Age