# Sarin, Hairu and Fatimah make greeting cards for Mother’s Day part 21 (Math Question)

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The blog postings are about the Singapore Math. The readers can learn from the postings on Solving Singapore Primary School Mathematics. The blog presenting the Math Concept, Math Questions with solutions that teaches in Singapore Primary Schools. You or the kids will learn the skill of dealing with Math Question Solving, Math Modeling and Problem Sums from Lower Primary School to Upper Primary School level after reading the blog postings. This posting is an upper primary school math question on Shape and Area.

You can read the story of Sarin and the siblings making greeting cards for their mother by reading the posting on Sarin, Hairu and Fatimah make greeting cards for Mother’s Day in Welcome page.

You can read the posting on Sarin learns Perimeter, Area and Volume in school(Math Concept) to learn the concept of area.

Challenge yourself with the question before look for the given solution‼!

Upper primary school mathematics question UPQ580

Sarin, Hairu and Fatimah made a greeting card for her mother. They made the greeting card as like a photo frame. They used 4 identical coloured rectangular shape papers and arrange them as the figure shown to make the frame of the greeting card.

The perimeter of each of the coloured rectangular shape paper is 30 cm and the inner square formed by the frame is 23 cm2 more than the total area of the coloured rectangular papers. Find the area of the inner square.

Solution:

Based on the arrangement of the rectangular papers shown in the figure

The  shape of the greeting card is a square

The outer length of the frame = The sum of the length and breadth one rectangular paper

Given the perimeter of one rectangular paper = 30 cm

The outer length = 30 ÷ 2 = 15 cm

The area of the greeting card = 15 × 15 = 225 cm2

From the model,

The area of 2 inner squares = 225 + 23 = 248 cm2

The area of an inner square = 248 ÷ 2 = 124 cm2

Or,

The area of 2 frames = 225 – 23 = 202 cm2

The area of the frame = 202 ÷ 2 = 101 cm2

The area of the inner square = 225 – 101 = 124 cm2