I can add and subtract decimals by lining up the place values and the decimal points.Puedo sumar y restar decimales alineando los valores posicionales y los puntos decimales.
MissionMisión · Summit TrailSendero a la cumbre
Every checkpoint gets you higher.Cada punto de control te lleva más alto.
You are a guide on Summit Trail. Every checkpoint reports distances, weights, and elevations as decimals, and you must add and subtract them exactly to keep each group on track.
Eres guía en Summit Trail. Cada punto de control informa distancias, pesos y elevaciones con decimales, y debes sumarlos y restarlos con exactitud para que cada grupo siga en el camino.
Word bankBanco de palabras 5 words5 palabrasdecimal, place value, tenths, …decimal, valor posicional, décimas, …
- decimaldecimal
- A number with a point that shows a part less than one whole.Un número con un punto que muestra una parte menor que un entero.
- place valuevalor posicional
- What a digit is worth because of where it sits in the number.Lo que vale un dígito por el lugar que ocupa en el número.
- tenthsdécimas
- The first place after the decimal point. It shows parts out of 10.El primer lugar después del punto decimal. Muestra partes de 10.
- hundredthscentésimas
- The second place after the decimal point. It shows parts out of 100.El segundo lugar después del punto decimal. Muestra partes de 100.
- annex zerosagregar ceros
- Write extra zeros at the right end of a decimal so the places line up. The value does not change.Escribir ceros extra al final de un decimal para que los lugares se alineen. El valor no cambia.
Stage 1 of 5Etapa 1 de 5
Get ReadyPrepárate
Wake up what you know, then explore today's model.
Activa lo que sabes y luego explora el modelo de hoy.
- Predict 46.8 − 3.75 on paper. Line up the decimal points and annex a zero to 46.8 first. Then set the Operation to 2 and compare the model's Answer with yours. Explain what the annexed zero did and why it does not change the value of 46.8.
- A trail sign says the next rest stop is 14.58 km away. In the number 14.58, what is the value of the digit 5?
- 5 hundredths
- 5 tenths
- 5 ones
- 50
- A hiker's water bottle holds 3.5 liters. Which number has the same value as 3.5?
- 3.50
- 3.05
- 35.0
- 3.005
- Two trail snacks weigh 0.8 kg and 0.75 kg. Which snack is heavier?
- The 0.75 kg snack
- They weigh the same
- The 0.8 kg snack
- You cannot tell without more digits
- 1 fresh problem with new numbers each time (interactive only).
Stage 2 of 5Etapa 2 de 5
Try ItInténtalo
Use the hints when you need them. Every wrong answer tells you why.
Usa las pistas cuando las necesites. Cada respuesta incorrecta te dice por qué.
- What is 14.6 + 3.85?
- 17.45
- 18.35
- 18.45
- 18.55
- What is 20.3 − 7.48?
- 12.18
- 12.82
- 12.92
- 13.82
- What is 9.05 + 4.7?
- 13.12
- 13.57
- 13.75
- 14.75
Stage 3 of 5Etapa 3 de 5
On Your OwnPor tu cuenta
Tables, mistakes to find, and problems with a few steps.
Tablas, errores por encontrar y problemas de varios pasos.
- A student buys items costing $4.59, $12.75, and $3.80. What is the total cost?
- $20.14
- $21.04
- $21.14
- $21.24
- Match each expression to its answer.
- Spot the Mistake — Subtracting Without a Placeholder
- What is the best next move?
- Line up the last digits of 14.6 and 3.75.
- Add the whole parts, 14 + 3, and the decimal parts, 6 + 75, separately and join them.
- Line up the decimal points and write 14.6 as 14.60.
- Add 146 + 375 and put the point back at the end.
Stage 4 of 5Etapa 4 de 5 · OptionalOpcional
Practice MorePractica más
Optional extra practice. Press New numbers for another problem on the same skill.
Práctica extra opcional. Toca Números nuevos para otro problema de la misma habilidad.
- 5 fresh problems with new numbers each time (interactive only).
Stage 5 of 5Etapa 5 de 5
Show What You KnowDemuestra lo que sabes
Show what you learned today. Take your time; you can try again.
Muestra lo que aprendiste hoy. Tómate tu tiempo; puedes intentarlo otra vez.
- 2.45 + 2.60 + 2.38 = ?
- 6.43
- 7.143
- 7.43
- 7.53
- Why is it safe to rewrite 2.6 as 2.60?
- It makes the number ten times bigger
- Adding a zero at the end of a decimal does not change its value
- It rounds the number up
- Because 6 and 60 use the same digit
- To subtract 2.348 from 6.5, which setup lines up the place values correctly?
- Write 6.5 as 6.005, then line up the decimal points.
- Line up the last digits: the 5 under the 8.
- Round 2.348 to 2.35 first, then line up the points.
- Write 6.5 as 6.500, then line up the decimal points.