First Grade Mental Math Worksheets - Free Printable
Educational worksheet: First Grade Mental Math Worksheets. Download and print for classroom or home learning activities.
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Step-by-step solution for: First Grade Mental Math Worksheets
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Show Answer Key & Explanations
Step-by-step solution for: First Grade Mental Math Worksheets
Here are the solutions to the math problems on the worksheet, solved step by step.
1) What is the total of 3, 5 and 6?
* Step 1: Add the first two numbers: $3 + 5 = 8$.
* Step 2: Add the last number to that result: $8 + 6 = 14$.
* The total is 14.
2) How many dimes make 25¢?
* A dime is worth 10 cents.
* Two dimes equal 20 cents ($10 + 10 = 20$).
* Three dimes equal 30 cents ($10 + 10 + 10 = 30$).
* Since 25 is between 20 and 30, you cannot make exactly 25 cents using only dimes. However, usually, this question asks how many dimes fit into 25 cents or if it's a trick question about making change. Let's look closer. Actually, looking at standard 2nd-grade logic, sometimes they ask "How many dimes are in 25 cents?" implying whole dimes. That would be 2. But often these questions imply exact change. Wait, let me re-read carefully. "How many dimes make 25¢?" You literally cannot make 25 cents with *only* dimes. Is it possible the question implies coins generally? No, it specifies dimes. Let's look at question 7. Question 7 asks about money with specific coins. Question 2 is likely asking for the maximum number of dimes that fit, which is 2, with 5 cents left over. OR, it is a trick question. Let's look at the context. It's a quiz. Usually, answers are integers. Let's assume it means "How many dimes are needed to get closest without going over?" -> 2. Or perhaps it's a typo for quarters? No. Let's look at similar problems online. Often, "How many dimes make 20 cents?" is the question. If it says 25, it might be testing if the student knows they *can't*. But typically, worksheets expect a number. Let's reconsider the wording. Could it be "How many coins make 25c if they are dimes and nickels?" No. Let's assume the question is flawed or I am missing a nuance. Let's look at the image again. Ah, I see "2) How many dimes make 25¢?". This is mathematically impossible with integers. However, in some contexts, students might answer "2" (meaning 2 dimes and some other change not mentioned) or "2.5" (which is too advanced). Let's look at question 7 again. It has specific coins. Question 2 is isolated. Let's look at the provided solution key logic for similar worksheets. Often, if it's "How many dimes in 25 cents", the answer is 2 remainder 5. If forced to give a single number, 2 is the most logical "whole number" answer representing the count of dimes used. *Self-correction*: Actually, looking at the level (Quiz 3.7), maybe it's a typo for 20¢ or 30¢? If it's 20¢, answer is 2. If 30¢, answer is 3. Given 25¢, the strict answer is "You can't." But for a homework helper, I should provide the most likely intended answer or explain the impossibility. Let's look at the next questions to gauge difficulty. Q3 is shapes. Q4 is counting legs. Q5 is subtraction. Q6 is multiplication. Q7 is money addition. Q8 is skip counting. Q9 is time. Q10 is place value/bundles.
* Let's re-evaluate Q2. Is it possible it means "How many *coins* make 25¢" and the word "dimes" is a typo for "coins"? If so, 1 quarter, or 2 dimes 1 nickel, etc. Too ambiguous.
* Let's assume the question asks "How many dimes are in 25 cents?" Answer: 2 (with 5 cents left over). I will provide 2 as the primary answer but note the remainder in my head. Actually, let's look at the visual cue. There is no visual cue. I will stick with 2 as the integer part, or perhaps the question meant quarters? 1 quarter makes 25. That fits perfectly. "How many quarters make 25¢?" -> 1. "How many dimes make 20¢?" -> 2. It is highly likely a typo for quarters or 20 cents. Given "dimes" is written, and 25 is written, it's a bad question. However, if I must answer, I will say 2 (as in 2 dimes is the closest amount less than 25). *Wait*, let's look at the prompt again. "Solve the problem accurately." Accurately, you cannot make 25 cents with dimes. But for a 2nd grader, maybe they want 2.5? No. Maybe they want 0? No. Let's guess the teacher made a typo for quarters. If it were quarters, the answer is 1. If it were nickels, the answer is 5. If it were pennies, 25. Dimes don't fit. I will provide the answer 2 with a small note that it doesn't add up exactly, or better yet, I will treat it as "How many full dimes fit in 25 cents". Answer: 2.
*Alternative interpretation*: Is it possible the question is "How many dimes make 20¢?" and the 5 is a smudge? No, it looks like 25.
*Let's try one more angle*: In some curricula, they teach that 2 dimes and 1 nickel make 25. But the question says "How many *dimes*".
*Decision*: I will provide 2 as the answer, assuming it asks for the maximum number of whole dimes.
3) Tick all the 3D shapes below.
* Circle: 2D (flat).
* Cylinder: 3D (has depth/volume). Tick.
* Cube: 3D (has depth/volume). Tick.
* Triangle: 2D (flat).
* Square: 2D (flat).
* Sphere (or ball shape shown): 3D. Tick.
* Rectangle: 2D (flat).
* The shapes to tick are the Cylinder, the Cube, and the Sphere/Ball.
4) How many more frogs than spiders?
* Count the frogs: There are 4 frogs.
* Count the spiders: There are 2 spiders.
* Subtract the number of spiders from the number of frogs: $4 - 2 = 2$.
* There are 2 more frogs than spiders.
5) How many legs do 3 frogs have?
* One frog has 4 legs.
* Multiply the number of frogs by the number of legs per frog: $3 \times 4$.
* $3 \times 4 = 12$.
* They have 12 legs.
6) 80 – 5 =
* Start at 80.
* Count back 5: 79, 78, 77, 76, 75.
* Alternatively: $80 - 5 = 75$.
7) I buy 2 packs of paper. Each pack has 10 sheets. How many sheets have I bought?
* Number of packs: 2.
* Sheets per pack: 10.
* Multiply: $2 \times 10 = 20$.
* I have bought 20 sheets.
8) How much money?
* Coins shown: Quarter (25¢), Dime (10¢), Nickel (5¢), Penny (1¢).
* Add them up: $25 + 10 + 5 + 1$.
* $25 + 10 = 35$.
* $35 + 5 = 40$.
* $40 + 1 = 41$.
* Total is 41¢.
9) 20 + 20 + 8 =
* First add the tens: $20 + 20 = 40$.
* Then add the ones: $40 + 8 = 48$.
* The sum is 48.
10) What is the next number in the sequence? 20, 18, 16, 14, 12, 10, ___
* Look at the pattern: The numbers are decreasing by 2 each time.
* $20 - 2 = 18$
* $18 - 2 = 16$
* $16 - 2 = 14$
* $14 - 2 = 12$
* $12 - 2 = 10$
* Next: $10 - 2 = 8$.
* The next number is 8.
11) What digit/time does the clock show?
* The hour hand (short hand) is pointing directly at the 3.
* The minute hand (long hand) is pointing directly at the 12.
* When the minute hand is on 12, it is "o'clock".
* The time is 3:00.
12) How many?
* There are bundles of sticks and loose sticks.
* Bundles: There are 3 bundles. In base-10 blocks/sticks, one bundle usually equals 10. So, $3 \times 10 = 30$.
* Loose sticks: There are 4 individual sticks.
* Total: $30 + 4 = 34$.
* There are 34 sticks.
Final Answer:
1) 14
2) 2 (Note: 2 dimes equal 20¢, which is the closest amount without going over. Exact change for 25¢ cannot be made with dimes alone.)
3) The Cylinder, the Cube, and the Sphere (ball shape).
4) 2
5) 12
6) 75
7) 20
8) 41¢
9) 48
10) 8
11) 3:00
12) 34
1) What is the total of 3, 5 and 6?
* Step 1: Add the first two numbers: $3 + 5 = 8$.
* Step 2: Add the last number to that result: $8 + 6 = 14$.
* The total is 14.
2) How many dimes make 25¢?
* A dime is worth 10 cents.
* Two dimes equal 20 cents ($10 + 10 = 20$).
* Three dimes equal 30 cents ($10 + 10 + 10 = 30$).
* Since 25 is between 20 and 30, you cannot make exactly 25 cents using only dimes. However, usually, this question asks how many dimes fit into 25 cents or if it's a trick question about making change. Let's look closer. Actually, looking at standard 2nd-grade logic, sometimes they ask "How many dimes are in 25 cents?" implying whole dimes. That would be 2. But often these questions imply exact change. Wait, let me re-read carefully. "How many dimes make 25¢?" You literally cannot make 25 cents with *only* dimes. Is it possible the question implies coins generally? No, it specifies dimes. Let's look at question 7. Question 7 asks about money with specific coins. Question 2 is likely asking for the maximum number of dimes that fit, which is 2, with 5 cents left over. OR, it is a trick question. Let's look at the context. It's a quiz. Usually, answers are integers. Let's assume it means "How many dimes are needed to get closest without going over?" -> 2. Or perhaps it's a typo for quarters? No. Let's look at similar problems online. Often, "How many dimes make 20 cents?" is the question. If it says 25, it might be testing if the student knows they *can't*. But typically, worksheets expect a number. Let's reconsider the wording. Could it be "How many coins make 25c if they are dimes and nickels?" No. Let's assume the question is flawed or I am missing a nuance. Let's look at the image again. Ah, I see "2) How many dimes make 25¢?". This is mathematically impossible with integers. However, in some contexts, students might answer "2" (meaning 2 dimes and some other change not mentioned) or "2.5" (which is too advanced). Let's look at question 7 again. It has specific coins. Question 2 is isolated. Let's look at the provided solution key logic for similar worksheets. Often, if it's "How many dimes in 25 cents", the answer is 2 remainder 5. If forced to give a single number, 2 is the most logical "whole number" answer representing the count of dimes used. *Self-correction*: Actually, looking at the level (Quiz 3.7), maybe it's a typo for 20¢ or 30¢? If it's 20¢, answer is 2. If 30¢, answer is 3. Given 25¢, the strict answer is "You can't." But for a homework helper, I should provide the most likely intended answer or explain the impossibility. Let's look at the next questions to gauge difficulty. Q3 is shapes. Q4 is counting legs. Q5 is subtraction. Q6 is multiplication. Q7 is money addition. Q8 is skip counting. Q9 is time. Q10 is place value/bundles.
* Let's re-evaluate Q2. Is it possible it means "How many *coins* make 25¢" and the word "dimes" is a typo for "coins"? If so, 1 quarter, or 2 dimes 1 nickel, etc. Too ambiguous.
* Let's assume the question asks "How many dimes are in 25 cents?" Answer: 2 (with 5 cents left over). I will provide 2 as the primary answer but note the remainder in my head. Actually, let's look at the visual cue. There is no visual cue. I will stick with 2 as the integer part, or perhaps the question meant quarters? 1 quarter makes 25. That fits perfectly. "How many quarters make 25¢?" -> 1. "How many dimes make 20¢?" -> 2. It is highly likely a typo for quarters or 20 cents. Given "dimes" is written, and 25 is written, it's a bad question. However, if I must answer, I will say 2 (as in 2 dimes is the closest amount less than 25). *Wait*, let's look at the prompt again. "Solve the problem accurately." Accurately, you cannot make 25 cents with dimes. But for a 2nd grader, maybe they want 2.5? No. Maybe they want 0? No. Let's guess the teacher made a typo for quarters. If it were quarters, the answer is 1. If it were nickels, the answer is 5. If it were pennies, 25. Dimes don't fit. I will provide the answer 2 with a small note that it doesn't add up exactly, or better yet, I will treat it as "How many full dimes fit in 25 cents". Answer: 2.
*Alternative interpretation*: Is it possible the question is "How many dimes make 20¢?" and the 5 is a smudge? No, it looks like 25.
*Let's try one more angle*: In some curricula, they teach that 2 dimes and 1 nickel make 25. But the question says "How many *dimes*".
*Decision*: I will provide 2 as the answer, assuming it asks for the maximum number of whole dimes.
3) Tick all the 3D shapes below.
* Circle: 2D (flat).
* Cylinder: 3D (has depth/volume). Tick.
* Cube: 3D (has depth/volume). Tick.
* Triangle: 2D (flat).
* Square: 2D (flat).
* Sphere (or ball shape shown): 3D. Tick.
* Rectangle: 2D (flat).
* The shapes to tick are the Cylinder, the Cube, and the Sphere/Ball.
4) How many more frogs than spiders?
* Count the frogs: There are 4 frogs.
* Count the spiders: There are 2 spiders.
* Subtract the number of spiders from the number of frogs: $4 - 2 = 2$.
* There are 2 more frogs than spiders.
5) How many legs do 3 frogs have?
* One frog has 4 legs.
* Multiply the number of frogs by the number of legs per frog: $3 \times 4$.
* $3 \times 4 = 12$.
* They have 12 legs.
6) 80 – 5 =
* Start at 80.
* Count back 5: 79, 78, 77, 76, 75.
* Alternatively: $80 - 5 = 75$.
7) I buy 2 packs of paper. Each pack has 10 sheets. How many sheets have I bought?
* Number of packs: 2.
* Sheets per pack: 10.
* Multiply: $2 \times 10 = 20$.
* I have bought 20 sheets.
8) How much money?
* Coins shown: Quarter (25¢), Dime (10¢), Nickel (5¢), Penny (1¢).
* Add them up: $25 + 10 + 5 + 1$.
* $25 + 10 = 35$.
* $35 + 5 = 40$.
* $40 + 1 = 41$.
* Total is 41¢.
9) 20 + 20 + 8 =
* First add the tens: $20 + 20 = 40$.
* Then add the ones: $40 + 8 = 48$.
* The sum is 48.
10) What is the next number in the sequence? 20, 18, 16, 14, 12, 10, ___
* Look at the pattern: The numbers are decreasing by 2 each time.
* $20 - 2 = 18$
* $18 - 2 = 16$
* $16 - 2 = 14$
* $14 - 2 = 12$
* $12 - 2 = 10$
* Next: $10 - 2 = 8$.
* The next number is 8.
11) What digit/time does the clock show?
* The hour hand (short hand) is pointing directly at the 3.
* The minute hand (long hand) is pointing directly at the 12.
* When the minute hand is on 12, it is "o'clock".
* The time is 3:00.
12) How many?
* There are bundles of sticks and loose sticks.
* Bundles: There are 3 bundles. In base-10 blocks/sticks, one bundle usually equals 10. So, $3 \times 10 = 30$.
* Loose sticks: There are 4 individual sticks.
* Total: $30 + 4 = 34$.
* There are 34 sticks.
Final Answer:
1) 14
2) 2 (Note: 2 dimes equal 20¢, which is the closest amount without going over. Exact change for 25¢ cannot be made with dimes alone.)
3) The Cylinder, the Cube, and the Sphere (ball shape).
4) 2
5) 12
6) 75
7) 20
8) 41¢
9) 48
10) 8
11) 3:00
12) 34
Parent Tip: Review the logic above to help your child master the concept of 1st grade math tests.
