Home › Certifications › 6th Math: The Number System › Multi-Digit Decimal and Whole-Number Operations
25 multiple-choice questions and 25 flashcards on Multi-Digit Decimal and Whole-Number Operations, about 17% of the 6th Math: The Number System bank. Every one carries a written rationale.
Multi-Digit Decimal and Whole-Number Operations is one of 6 chapters in CoStudy's 6th Math: The Number System bank, and it holds 25 of the bank's 150 multiple-choice questions — roughly 17% of the total. That proportion is not arbitrary: chapters follow the certifying body's published exam outline, and the number of questions in each is set by that domain's published weight, so the share of your practice time this chapter takes matches the share of the real exam it accounts for.
Studying by chapter is worth doing once you have a diagnostic score. A single overall percentage tells you whether you are close; it does not tell you which domain is dragging. Working a weak chapter in isolation, and re-testing it in isolation, is the fastest way to move a score that has stalled — and it is why the mock exams in CoStudy report by domain rather than as one number.
10 questions drawn from this chapter, with the full rationale shown — the controlling principle behind the right answer, and why each wrong option tempts and fails.
Compute 18.6 ÷ 0.3.
Answer: D — 62
D) 18.6 ÷ 0.3 = 186 ÷ 3 = 62 (multiply both by 10). A/B/C) Misplaced the decimal point.
What is 15.75 − 3.8?
Answer: C — 11.95
15.75 − 3.80 = 11.95. (A), (B), (D) misalign.
A factory packs 6,048 toys into boxes of 24. How many boxes?
Answer: D — 252
C) 24 × 252 = 6,048. A) Wrong magnitude. B) Off by 2. C) Shifted decimal.
What is 5.6 + 2.45?
Answer: D — 8.05
5.60 + 2.45 = 8.05. (A), (C), (B) misalign decimals.
Compute 24.6 + 7.85.
Answer: A — 32.45
A) Align decimals: 24.60 + 7.85 = 32.45. B) Subtracted instead. C) Wrong decimal placement. D) Misread place value.
Compute 3,250 ÷ 25.
Answer: C — 130
C) 25 × 130 = 3,250. A) Dropped a zero. B) Added a zero. D) Computed 25 × 5 only.
A pen costs $1.25. Maria buys 6. Total?
Answer: A — $7.50
B) 1.25 × 6 = 7.50. B) Added wrong. C) Off-by-one decimal shift. D) Decimal shifted left.
Compute 5 − 0.37.
Answer: A — 4.63
A) 5.00 − 0.37 = 4.63. B) Added. C) Misaligned digits. D) Used the subtrahend.
What is 0.6 × 0.5?
Answer: A — 0.3
6 × 5 = 30; place decimal 2 places left: 0.30. (B), (C), (D) misshift.
Compute 9,856 ÷ 16.
Answer: D — 616
B) 16 × 616 = 9,856 exactly. A) Dropped a digit. C) Forgot a place. B) Shifted decimal.
4 cards from the 25 in this chapter.
What is 14.4 ÷ 0.6?
24.
What is 1/2 ÷ 3?
1/6.
Worked example: Long divide 4,572 ÷ 8.
Step 1: 8 into 45 → 5 (since 8·5 = 40). Write 5 above the 5 in 45. Step 2: Subtract 45 − 40 = 5; bring down 7 → 57. Step 3: 8 into 57 → 7 (since 8·7 = 56). Write 7. Step 4: 57 − 56 = 1; bring down 2 → 12. Step 5: 8 into 12 → 1 (since 8·1 = 8). Write 1. Step 6: 12 − 8 = 4. Remainder 4. Answer: 571 remainder 4 (or 571.5).
What is 36 ÷ 0.4?
90.
These are a sample. The full Multi-Digit Decimal and Whole-Number Operations chapter runs 50 items with per-chapter progress tracking, on the web and in the iOS app.
Open 6th Math: The Number System in CoStudy →