Your child can add whole numbers confidently. Then their Maths homework asks them to calculate $4.75 + $2.60, and they write $6.135.

Perhaps they know that 0.5 is one half but insist that 0.45 is greater because 45 is greater than 5. You explain the answer, yet the next decimal question causes the same confusion.

This is often a place value problem. Your child may be treating the digits after the decimal point as a separate whole number rather than parts of one whole.

If your child is in Grade 5 in Ontario, a few everyday money questions can help you discover what they understand before asking them to complete more calculations.

Start with what each digit means

Write $4.75 on a piece of paper. Ask your child what each part represents.

It is 4 dollars, 7 tenths of a dollar and 5 hundredths of a dollar. In money terms, the digits after the decimal point represent 75 cents.

Now write $4.07. This is 4 dollars and 7 cents—not 4 dollars and 70 cents. The zero holds an important place.

If your child can read the numbers aloud but cannot explain the difference, pause the addition homework and work on place value first.

Three questions to try together

Give your child time to explain their answers. They can draw a place value chart or use an example involving dollars and cents.

1. Which amount is greater?

Question: Which is greater: $3.50 or $3.45?

Answer: $3.50 is greater by 5 cents.

Ask your child to compare the dollars first, then the cents. Both amounts have three dollars; 50 cents is more than 45 cents.

2. Does a zero change the value?

Question: Are 0.5 and 0.50 equal?

Answer: Yes. Five tenths is the same amount as fifty hundredths. In money, $0.50 is 50 cents.

If your child says 0.50 must be larger because it has more digits, use a drawing divided into tenths and hundredths to show the same shaded amount.

3. What is the total cost?

Question: A notebook costs $4.75 and a pen costs $2.60. How much do they cost altogether?

Answer: $7.35.

One method is to add the dollars and cents separately: $4 + $2 = $6, and 75¢ + 60¢ = 135¢, which is $1.35. The total is $7.35.

Ask whether the answer seems reasonable. Two items costing about $5 and $3 should total about $8. An answer of $6.135 should prompt a second look.

Why lining up decimal points matters

When adding 4.75 + 2.60, your child needs to combine amounts with the same place value: hundredths with hundredths, tenths with tenths and ones with ones.

A place value chart can help:

OnesTenthsHundredths475260

The digits are lined up by what they represent, not simply by where there is space on the page.

Once your child understands that, practising the written calculation becomes more meaningful.

Try a change problem at home

Ask:

“You have $10.00 and spend $6.35. How much money remains?”

The answer is $3.65.

Your child might subtract, or they might count up from $6.35: add 65 cents to reach $7.00, then add $3.00 to reach $10.00. Both approaches can show useful reasoning.

If they can solve it with coins or a drawing but not on paper, the next goal is connecting their practical understanding to decimal notation.

When is extra support useful?

Speak with your child’s teacher if they repeatedly confuse tenths and hundredths, make the same errors with money, or cannot explain what a decimal answer means. Share a recent assignment and ask which place value skill should be practised first.

A Maths tutor should look beyond whether an answer