SME
Grade 3 Math · Problem type
Measure to the nearest quarter inch
Use this for “What is the length of the rectangle?” to the quarter inch.
Diagram
Whole inches: 2
Marks past the last inch: 1
This is an example. Type your own values to start a new problem.
Marks after 0
example
Marks in one inch
example
Whole inches
calculated
Marks past the last inch
calculated
Formulas
9
marks
of
1
4
inch
pass
2
whole
inches
Full inches in the marks after 0 = whole inches
9 marks = 2 inches of 4 marks and 1 mark
Marks after 0 = whole inches × marks in one inch + marks past the last inch
Assumptions
•
Each inch on the ruler is split into equal marks: 2 for halves, 4 for quarters.
•
Count the marks after 0, up to the end of the object. The 0 mark is not counted.
•
Every full set of marks is 1 inch; the marks left over are the fraction of an inch.
Step-by-step
WE KNOW
Marks after 0: 9
Marks in one inch: 4
FIND
whole inches, marks past the last inch
Step 1 · Find whole inches
9
marks
of
1
4
inch
pass
?
whole
inches
Full inches in the marks after 0 = whole inches
Every full set of marks makes 1 inch. Count the full sets.
Count by 4s: 4, 8 → 2 inches
Whole inches = 2
Step 2 · Find marks past the last inch
9 marks = 2 inches of 4 marks and ? marks
Marks after 0 = whole inches × marks in one inch + marks past the last inch
Take away the marks that make whole inches. The rest are left over.
Marks past the last inch = 9 − 2 × 4
2 × 4 = 8
9 − 8 = 1
Marks
past
the
last
inch
=
1
(
2
1
4
inches
long)
Check
Put the numbers back in. Both sides should match.
9
marks
of
1
4
inch
pass
2
whole
inches
✓
9 marks = 2 inches of 4 marks and 1 mark ✓
Topic check
See what you know: 5 questions on this topic
New questions each time. Pass to mark it complete.