π

How rewards work

📒 See my notebook: everything I've played

XP: 0 in all · Level 1

Every right answer gives you XP: 6 on the easiest questions, up to 14 on the hardest, plus 2 more for each answer in a row (up to +10). Lessons you've already mastered give half, so try something new for the most! Every 200 XP, you reach a new level.200 XP to Level 2

Coins: 0

Earn 5 coins for each star in Practice. In Math Race, get 10 for a win or 5 for finishing. In Monster Battle, get 10 for beating the monster or 3 for trying. In Asteroid Blaster, get 10 for finishing a mission or 3 for trying. Every Maze Quest gives 10. Spend them in Digit's House on hats, glasses, mustaches, pets, room decorations, and big room makeovers!

Streak: 0 days

Finish a game on different days in a row to grow your streak. Miss a day and it starts over, unless you have a 🛡️ streak shield from Digit's House: it saves your streak for one missed day (you can keep 2).

Badges

Earn badges for big moments: your first 3-star round, beating every monster, a 7-day streak, finding treasures, and more. See them all, and how close you are, on the badge wall in Digit's House.

Difficulty

Get 3 right in a row and questions get trickier. Miss 2 in a row and they get easier. Each skill remembers where you are.

The games

Practice

10 questions. Get most of them right for up to 3 stars. Use a hint if you're stuck.

Math Race

Get 10 right to reach the finish before Digit. A wrong answer doesn't move you back, but the clock keeps ticking. Win and Digit gets faster next time.

Monster Battle

The monster has 8 HP and you have 3 hearts. Each right answer throws something silly at it. Get 2 in a row to switch on ⚡ super power: then every hit does double damage until you miss. A wrong answer lets the monster take a heart. No clock, so take your time.

Asteroid Blaster

10 waves of falling asteroids, each with an answer. Tap the right one to blast it. Faster shots and streaks score more points. You have 3 shields: a wrong tap or a missed asteroid uses one.

Maze Quest

Help Digit through a maze with 8 locked doors. Answer to open each door; open it on the first try for a 💎. No clock and no lives: a wrong answer just means a new question. A treasure waits at the end. Can you find all 12?

Daily Challenge

One puzzle a day, the same for everyone in your grade. Your first try counts and earns 15 coins. Do one every day to grow your Daily streak, and share your result card with family!

Brain Break

A break from math: two fun questions about animals, space, our world, and more, every day. Each right answer earns 5 coins, and you'll learn a cool fact either way.

Challenge a friend

After a game, send a link. Your friend gets the exact same questions and tries to beat your score.

Settings

Read questions out loud
🔊 Read questions out loud by itself

The 🔊 button is on every question in every grade, so anyone can tap it to hear one. This setting only decides when questions are read without tapping.

Voices come from this device and browser. Ones marked “Natural”, “Neural”, or “Google” sound most like a real person. Microsoft Edge has extra natural voices built in. Pets, monsters, and Nibbles each get their own pitch and speed.

📲 Install the appOpen agarwalmath from the home screen, full screen, like an app. Free, no app store.How to install
← Find the missing side
Level:EasierLevel 2Level 3Level 4Harder
🔀 Make a different worksheet

12 questions and an answer key (on the last page). Free to print and share with your class or family.

πagarwalmath · 4th grade · Common Core 4.MD.A.3

📏 Find the missing side

Area and perimeter formulas

Name: ______________________Date: ____________

  1. 1A rectangle has an area of 64 square cm. One side is 8 cm. How long is the other side?

    Answer: ______________ cm

  2. 2A rectangle has a perimeter of 50 cm. One side is 10 cm. How long is the side next to it?

    Answer: ______________ cm

  3. 3A rectangle has an area of 88 square cm. One side is 22 cm. How long is the other side?

    Answer: ______________ cm

  4. 4A rectangle has an area of 143 square cm. One side is 11 cm. How long is the other side?

    Answer: ______________ cm

  5. 5A rectangle has a perimeter of 68 cm. One side is 10 cm. How long is the side next to it?

    Answer: ______________ cm

  6. 6A rectangle has a perimeter of 44 cm. One side is 11 cm. How long is the side next to it?

    Answer: ______________ cm

  7. 7A rectangle has a perimeter of 28 cm. One side is 9 cm. How long is the side next to it?

    Answer: ______________ cm

  8. 8A rectangle has a perimeter of 68 cm. One side is 20 cm. How long is the side next to it?

    Answer: ______________ cm

  9. 9A rectangle has an area of 108 square cm. One side is 9 cm. How long is the other side?

    Answer: ______________ cm

  10. 10A rectangle has an area of 483 square cm. One side is 23 cm. How long is the other side?

    Answer: ______________ cm

  11. 11A rectangle has a perimeter of 42 cm. One side is 14 cm. How long is the side next to it?

    Answer: ______________ cm

  12. 12A rectangle has an area of 14 square cm. One side is 2 cm. How long is the other side?

    Answer: ______________ cm

Answer key: Find the missing side

  1. 1. 8 cm
  2. 2. 15 cm
  3. 3. 4 cm
  4. 4. 13 cm
  5. 5. 24 cm
  6. 6. 11 cm
  7. 7. 5 cm
  8. 8. 14 cm
  9. 9. 12 cm
  10. 10. 21 cm
  11. 11. 7 cm
  12. 12. 7 cm

Practice this lesson online with games that adjust to your child: agarwalmath.com/math/4th-grade/measure-missing-side

agarwalmath.com · free K–5 math games, no adsClass code: ____________

All 4th grade lessons and worksheets